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Özet: Yumurta sarısı, özellikle memeli türlerine ait sperm hücrelerinin dondurularak saklanmasında kullanılan sulandırıcıların en yaygın kriyoprotektif bileşenlerinden biridir. Dolayısıyla, balık sperm hücrelerinin dondurularak saklanmasındaki etkinlikleri hakkında bilgi eksikliği bulunmaktadır. Bu nedenle bu çalışmanın amacı, farklı kanatlı türlerine (ördek, kaz ve tavuk) ait yumurta sarılarının, kriyoprezervasyonu takiben pullu sazan (Cyprinus carpio) spermasının çözüm sonu kalite ve fertilizasyon yeteneği üzerindeki etkinliklerinin karşılaştırılmasıydı. Sukroz bazlı sulandırıcı ile 1:10 oranında dilüe edilen sperm örneklerine %10, 15 ve %20 oranlarında farklı kanatlı yumurtası sarıları ilave edildi. Kontrol grubunda ise sperm örnekleri, yumurta sarısı içermeyen sukroz bazlı sulandırıcı ile dilüe edildi. Dilüsyon işlemini takiben, sperm örnekleri +4⁰C'de 10 dakika ekilibere edilerek 0,25 ml'lik payetlere çekildi. Daha sonra sperm hücreleri sıvı nitrojen (LN2) yüzeyinin 3 cm üzerinde dondurularak doğrudan sıvı azota (LN2) aktarıldı. Dondurulan sperm hücreleri 35 ⁰C su banyosunda 30 sn süre ile çözdürüldü ve 1x105 spermatozoa/yumurta oranı kullanılarak fertilizasyon işlemi gerçekleştirildi. Sonuçlara göre, sperm hücreleri sukroz bazlı sulandırıcıda %20 ördek yumurtası sarısı ile takviye edildiğinde, kontrol grubu ile karşılaştırıldığında en iyi çözüm sonu progresif motilite (%67,8 ±1,24), progresif motilite süresi (32,6 ±1,45 s), canlılık (%82,4 ±1,36) ve fertilite (%92,6 ±1,28) değerleri elde edilmiştir (P, Egg yolk is one of the most widely used cryoprotective components of extenders, especially for the cryopreservation of mammalian species’ sperm cells. However, there is a lack of information regarding their efficacy in cryopreservation of fish sperm cells. Thus, the objective of this experiment was to compare the effectiveness of egg yolk from different avian species (duck, goose, and chicken) on post-thaw quality and fertilization ability of scaly carp (Cyprinus carpio) semen following cryopreservation. Sperm samples diluted with the sucrose-based extender at the ratio of 1:10 were supplemented with 10, 15, and 20% ratios of different avian egg yolks. In the control group, sperm samples were diluted with the sucrose-based extender, without egg yolk. Following dilution, sperm samples were equilibrated at +4⁰C for 10 min and aspirated into 0.25-ml straws. Then, sperm samples were frozen 3 cm above the liquid nitrogen (LN2) surface and plunged directly into the LN2. The frozen sperm cells were thawed in a water bath at 35 ⁰C for 30 s and fertilization was carried out using a 1x105 spermatozoa/egg ratio. Based on the results, supplementation of sperm cells with 20 % duck egg yolk in a sucrose-based extender exhibited the best post-thaw progressive motility (67.8 ±1.24%), progressive motility duration (32.6 ±1.45 s), viability (82.4 ±1.36%), and fertility (92.6 ±1.28%) compared to the control group (P

Background Cryptorchidism (CPT) is an important cause of male infertility. Rubus apetalus is a medicinal plant with a powerful antioxidant potential. We investigated the effects of aqueous and methanolic extracts of R. apetalus on spermatozoa parameters, antioxidant enzymes and fertility potential of rats with experimental unilateral CPT. Method Normal (n = 15), sham-operated (n = 15) and cryptorchid rats (n = 80; distributed into 16 groups of 5 rats/group) were treated for 2, 4 or 8 weeks with either distilled water (10 ml/kg/day), vitamin E (75 mg/kg/day), aqueous or methanolic extract of R. apetalus (12 and 60 mg/kg). Sex organ weights, spermatozoa parameters, testicular proteins, sex hormones, fertility potential, morphometric characteristics of testis and oxidative stress markers were measured. Results CPT significantly (p p R. apetalus. For instance, a significantly increase (p R. apetalus also increased (p Conclusion R. apetalus boosts fertility potential in cryptorchid rats and could be considered as a promising alternative agent for the management of infertility associated with CPT.

We consider a minimalist model for the Sterile Insect Technique (SIT), assuming that residual fertility can occur in the sterile male population.Taking into account that we are able to get regular measurements from the biological system along the control duration, such as the size of the wild insect population, we study different control strategies that involve either continuous or periodic impulsive releases. We show that a combination of open-loop control with constant large releases and closed-loop nonlinear control, i.e. when releases are adjusted according to the wild population size estimates, leads to the best strategy in terms both of number of releases and total quantity of sterile males to be released.Last but not least, we show that SIT can be successful only if the residual fertility is less than a threshold value that depends on the wild population biological parameters. However, even for small values, the residual fertility induces the use of such large releases that SIT alone is not always reasonable from a practical point of view and thus requires to be combined with other control tools. We provide applications against a mosquito species, \textit{Aedes albopictus}, and a fruit fly, \textit{Bactrocera dorsalis}, and discuss the possibility of using SIT when residual fertility, among the sterile males, can occur.

Background Egg quality can be defined as the egg ability to be fertilized and subsequently develop into a normal embryo. Previous research has shed light on factors that can influence egg quality. Large gaps however remain including a comprehensive view of what makes a bad egg. Initial development of the embryo relies on maternally-inherited molecules, such as transcripts, deposited in the egg during its formation. Bad egg quality is therefore susceptible to be associated with alteration or dysregulation of maternally-inherited transcripts. We performed transcriptome analysis on a large number (N = 136) of zebrafish egg clutches, each clutch being split to monitor developmental success and perform transcriptome analysis in parallel. We aimed at drawing a molecular portrait of the egg in order to characterize the relation between egg transcriptome and developmental success and to subsequently identify new candidate genes involved in fertility. Results We identified 66 transcript that were differentially abundant in eggs of contrasted phenotype (low or high developmental success). Statistical modeling using partial least squares regression and genetics algorithm demonstrated that gene signatures from transcriptomic data can be used to predict developmental success. The identity and function of differentially expressed genes indicate a major dysregulation of genes of the translational machinery in poor quality eggs. Two genes, otulina and slc29a1a, predominantly expressed in the ovary and dysregulated in poor quality eggs were further investigated using CRISPR/Cas9 mediated genome editing. Mutants of each gene revealed remarkable subfertility whereby the majority of their eggs were unfertilizable. The Wnt pathway appeared to be dysregulated in the otulina mutant-derived eggs. Conclusions Here we show that egg transcriptome contains molecular signatures, which can be used to predict developmental success. Our results also indicate that poor egg quality in zebrafish is associated with a dysregulation of (i) the translational machinery genes and (ii) novel fertility genes, otulina and slc29a1a, playing an important role for fertilization. Together, our observations highlight the diversity of the possible causes of egg quality defects and reveal mechanisms of maternal origin behind the lack of fertilization and early embryonic failures that can occur under normal reproduction conditions. Electronic supplementary material The online version of this article (10.1186/s12864-019-5930-8) contains supplementary material, which is available to authorized users.

A large amount of chemicals are released to the environment each year. Among them, bisphenol A (BPA) is of utmost concern since it interferes with the reproductive system of wild organisms due to its capacity to bind to hormone receptors. Additionally, BPA epigenotoxic activity is known to affect basic processes during embryonic life. However, its effects on primordial germ cells (PGCs) proliferation and migration, both mechanisms being crucial for gametogenesis, remain unknown. To investigate the effects of BPA on PGCs migration and eventual testicle development, zebrafish embryos were exposed to 100, 2000 and 4000 &micro, g/L BPA during the first 24 h of development. Vasa immunostaining of PGCs revealed that exposure to 2000 and 4000 &micro, g/L BPA impaired their migration to the genital ridge. Two pivotal genes of PGCs migration (cxcr4b and sdf1a) were highly dysregulated in embryos exposed to these doses, whereas DNA methylation and epigenetic marks in PGCs and their surrounding somatic cells were not altered. Once embryos reached adulthood, the morphometric study of their gonads revealed that, despite the reduced number of PGCs which colonized the genital ridges, normal testicles were developed. Although H3K9ac decreased in the sperm from treated fishes, it did not affect the progeny development.

Oviparous vertebrates produce multiple forms of vitellogenin (Vtg), the major source of yolk nutrients, but little is known about their individual contributions to reproduction and development. This study employed a CRISPR/Cas9 genome editing to assess essentiality and functionality of zebrafish (Danio rerio) type-I and -III Vtgs. The multiple CRISPR approach employed to knock out (KO) all genes encoding type-Ivtgs(vtg1, 4, 5, 6,and7) simultaneously (vtg1-KO), and the type-IIIvtg(vtg3) individually (vtg3-KO). Results of PCR genotyping and sequencing, qPCR, LC-MS/MS and Western blotting showed that onlyvtg6andvtg7escaped Cas9 editing. In fish whose remaining type-Ivtgswere incapacitated (vtg1-KO), and invtg3-KO fish, significant increases in Vtg7 transcript and protein levels occurred in liver and eggs, a heretofore-unknown mechanism of genetic compensation to regulate Vtg homeostasis. Fecundity was more than doubled invtg1-KO females, and fertility was ~halved invtg3-KO females. Substantial mortality was evident invtg3-KO eggs/embryos after only 8 h of incubation and invtg1-KO embryos after 5 d. Hatching rate and timing were markedly impaired invtgmutant embryos and pericardial and yolk sac/abdominal edema and spinal lordosis were evident in the larvae, with feeding and motor activities also being absent invtg1-KO larvae. By late larval stages,vtgmutations were either completely lethal (vtg1-KO) or nearly so (vtg3-KO). These novel findings offer the first experimental evidence that different types of vertebrate Vtg are essential and have disparate requisite functions at different times during both reproduction and development.

Eighteen (18) lactating she-camels and two mature male for mating were used to determine the effect of Management System on camel calving interval, The camels were maintained under semi-intensive (N = 9) and Traditional management system (N = 9) in North Kordofan State, western Sudan. The experimental females in each group kept together with the bull during 18 months. Blood samples were collected from jugular vein since 4-months post-partum and continue 14 successive months at monthly interval. The serum samples were separated and stored at -20°C and were analysed for progesterone concentration using progesterone specific radio immuno assay (RIA) kits. The results indicated that under semi-intensive system 77.8% of females had been pregnant in 5th - 8th month post-partum and the calving interval varying between 17 to 20 months. Under traditional system and during the experimental period 44.5% of females were pregnant in the 11th – 16th month and the calving interval varying between 23 to 28 months. The ratios of pregnant vs non-pregnant during experimental period in semi-intensive and traditional were 88.9% vs 11.1% and 44.5% vs 55.5%, respectively. Beside the behavioural signs progesterone level consider a good indicator for pregnancy in camels. In pregnant females Progesterone concentration increased significantly during early months. The range of Progesterone concentration varied between 1.10 – 5.76 ng/ml and 0.67 – 2.53 ng/ml in semi-intensive and traditional system, respectively. Our results allow quantifying this impact. With a supplemented diet including 2 Kg of concentrates and 5 kg of roughages per day, the fertility rate will be improved of 67%. It would be possible to expect more than two fold young camels in a year by supplemented 5 kg of concentrates. We conclude that under semi-intensive management dietary supplement during post-partum and early lactation period improves reproductive parameters for instance shortened calving interval.

The antestia bugAntestiopsis thunbergii(Gmelin 1790) is a major coffee pest in East Africa. Nymphs and adults feed on all vegetative and fruiting parts of the coffee tree leading to yield reduction and poor quality of coffee beans. Our study aimed to characterize the developmental biology and provide life table parameters forA. thunbergiireared in the laboratory. The biology ofA. thunbergiiwas studied at four constant temperatures of 20, 25, 30 and 35°C with 80±5% RH and a photoperiod of L:D 12:12. Complete development ofA. thunbergiifrom egg to adult occurred between 20 and 30°C, while eggs did not hatch at 35°C. Immature stage development time decreased significantly with an increase in temperature, with the exception of fifth nymphal stage, duration of which was similar for all temperatures. The fecundity was maximal at 20°C with an average of 132.8 eggs per female and 1.7 egg per female per day. The gross reproductive rate (GRR) was the highest at 20°C with 75.79 daughters per female compared to 19.56 and 2.69 daughters per female at 25 and 30°C, respectively. The intrinsic rate of increaserwas maximal at 20°C with 0.013 and negative at 30°C. The time required for the reared population to double (doubling timeTd) was shorter at 20°C with 53.31 days compared to 115.52 days at 25°C. Our study provides basic information onA. thunbergiibiology that will contribute to a better understanding of the pest distribution and dynamics on arabica coffee in East Africa.

International audience; There is increasing evidence that environmental exposures early in fetal development influence phenotype and give rise to disease risk in the next generations. We previously found that lifelong exposure to uranium, an environmental contaminant, induced subtle testicular and hormonal defects; however, its impact on the reproductive system of multiple subsequent generations was unexplored. Herein, rats were exposed to a supra-environmental and non-nephrotoxic concentration of natural uranium (U, 40 mg·L−1 of drinking water) from postnatal life to adulthood (F0), during fetal life (F1), and only as the germ cells from the F1 generation (F2). General parameters (reproductive indices, epididymal weight) and sperm morphology were assessed in the three generations. In order to identify the epigenetic effects of U, we analyzed also the global DNA methylation profile and described for the first time the mRNA expression levels of markers involved in the (de)methylation system in rat epididymal spermatozoa. Our results showed that the F1 generation had a reduced pregnancy rate. Despite the sperm number being unmodified, sperm morphology was affected in the F0, F1 and F2 generations. Morphometric analysis for ten parameters was detailed for each generation. No common parameter was detected between the three generations, but the head and the middle-piece were always modified in the abnormal sperms. In the F1 U-exposed generation, the total number of abnormal sperm was significantly higher than in the F0 and F2 generations, suggesting that fetal exposure to uranium was more deleterious. This effect could be associated with the pregnancy rate to produce the F2 generation. Interestingly, global DNA methylation analysis showed also hypomethylation in the sperm DNA of the last F2 generation. In conclusion, our study demonstrates that uranium can induce morphological sperm defects and changes in the DNA methylation level after multigenerational exposure. The epigenetic transgenerational inheritance of U-induced reproductive defects should be assessed in further experiments.; Il existe de plus en plus de preuves de ce que les expositions environnementales auxquelles les individus sont soumis durant leur développement influencent le phénotype et le risque d’apparition de maladies chez les générations futures. Nous avons précédemment constaté que l’uranium, un contaminant environnemental, induisait après une exposition durant la vie entière de subtiles anomalies testiculaires et hormonales, mais son impact sur le système reproducteur des générations suivantes restait inexploré. Dans cette étude, des rats ont été exposés à une concentration supra-environnementale et non néphrotoxique d’uranium (U, 40 mg·L−1 dans l’eau de boisson) de la vie postnatale à l’âge adulte (F0), pendant la vie fœtale (F1), et seulement en tant que cellules germinales de la génération F1 (F2). Les paramètres généraux (indices reproductifs, poids) et la morphologie des spermatozoïdes ont été évalués sur les trois générations. Afin d’identifier les effets épigénétiques de l’uranium, nous avons également analysé le profil global de méthylation de l’ADN et décrit, pour la première fois, les niveaux d’expression d’ARNm des marqueurs impliqués dans le système de (dé)méthylation des spermatozoïdes épididymaires de rats. Nos résultats ont montré que la génération F1 avait un taux de naissance réduit. Bien que le nombre de spermatozoïdes n’ait pas été modifié, la morphologie des spermatozoïdes a été affectée chez les générations F0, F1 et F2. L’analyse morphométrique de dix paramètres a été détaillée pour chaque génération. Aucun paramètre commun n’a été détecté entre les trois générations, mais la tête et la pièce intermédiaire ont toujours été modifiées dans ces spermatozoïdes anormaux. Chez les générations F1 exposées à l’U, le nombre total de spermatozoïdes anormaux était significativement plus élevé que chez les générations F0 et F2, ce qui suggère que l’exposition fœtale à l’uranium était plus nocive et pouvait affecter le taux de naissance pour produire la génération F2. Il est intéressant de noter aussi que l’analyse globale de méthylation de l’ADN a montré une hypométhylation dans l’ADN des spermatozoïdes de la dernière génération F2. En conclusion, notre étude démontre que l’uranium peut induire des défauts morphologiques des spermatozoïdes et un changement de méthylation de l’ADN après une exposition multigénérationnelle. La transmission transgénérationnelle épigénétique des anomalies du système reproducteur induites par l’uranium devra être évaluée dans de futures expériences.

There is substantial evidence that paternal obesity is associated not only with an increased incidence of infertility, but also with an increased risk of metabolic disturbance in adult offspring. Apparently, several mechanisms may contribute to the sperm quality alterations associated with paternal obesity, such as physiological/hormonal alterations, oxidative stress, and epigenetic alterations. Along these lines, modifications of hormonal profiles namely reduced androgen levels and elevated estrogen levels, were found associated with lower sperm concentration and seminal volume. Additionally, oxidative stress in testis may induce an increase of the percentage of sperm with DNA fragmentation. The latter, relate to other peculiarities such as alteration of the embryonic development, increased risk of miscarriage, and development of chronic morbidity in the offspring, including childhood cancers. Undoubtedly, epigenetic alterations (De plus en plus de données tendent à montrer que l’obésité paternelle a non seulement des effets néfastes sur la santé métabolique et reproductive de l’individu mais également sur celle de sa descendance. Les mécanismes mis en jeu dans ce processus incluraient des altérations physiologiques et hormonales des fonctions reproductives de l’homme obèse ainsi que des altérations épigénétiques au niveau du génome spermatique. Les modifications hormonales associées à l’obésité et qui se caractérisent principalement par une réduction du taux d’androgènes et une augmentation du niveau d’estrogène induiraient une altération des paramètres spermatiques, une diminution de la concentration ou de la numération totale en spermatozoïde et du volume séminal. Le stress oxydatif dans le testicule induirait une augmentation de la fragmentation de l’ADN spermatique et pourrait rendre compte de l’augmentation des risques de fausses-couches, des problèmes de développement embryonnaire ainsi que de l’augmentation des risques de mortalité chez la descendance, problèmes fréquemment rencontrés lorsque le père est. obèse. Les modifications épigénétiques (altérations des profils de méthylation de l’ADN, de la structure de la chromatine ou/et des profils d’expression des ARN spermatiques) induites par l’obésité sont, quant à elles, loin d’être comprises, même si elles sont, surement, les vecteurs clés de la transmission épigénétique paternelle des maladies métaboliques. L’objet de cette revue est. de résumer puis de discuter les différentes études expérimentales et épidémiologiques publiés à ce jour sur les conséquences physiologiques et moléculaire de l’obésité paternelle sur la santé de l’individu et sur celle de sa descendance.

The present study aimed to assess and measure the effects of breed, genetic merit for production traits, and feeding systems (FS) on the ability of dairy cows to ensure pregnancy through its components (fertilization, embryonic losses, recalving). An experiment was conducted over 9 yr on Normande and Holstein cows assigned to contrasted FS. Diets were based on maize silage in winter and grazing plus concentrate in spring in the high FS group, and on grass silage in winter and grazing with no concentrate during spring in the low FS group. Within breeds, cows were classified into 2 groups with similar estimated breeding values (EBV) for milk solids: cows with high EBV for milk yield were included in a milk group and those with high EBV for fat and protein contents were included in a content group. Holstein cows produced more milk throughout lactation than Normande cows (the differential was greater in the high FS group, +2,294 kg, compared with +1,280 kg in the low FS group) and lost more body condition to nadir (the differential was greater in the high FS group, -1.00 point, compared with -0.80 point in the low FS group). Within breeds, milk solids production was similar between genetic groups. Cows in the high FS group produced more milk (+2,495 kg for Holstein and +1,481 kg for Normande cows) and had a higher body condition score at nadir (+0.40 point for Holstein and +0.60 point for Normande) than cows in the low FS group. Holstein cows had a lower recalving rate than Normande cows (-19 percentage units). We found no effect of genetic group and FS on fertility of Normande cows. However, according to FS, Holstein cows in the content group exhibited different fertility failure patterns. In the low FS group, Holstein cows in the content group had more nonfertilizations or early embryo mortality (+26 percentage units at first and second services) than Holstein cows in the milk group. In the high FS group, Holstein cows in the content group had a higher proportion of late embryo mortality than in the milk group (+10 percentage units at first and second services). We observed no effect of FS on recalving rate; however, indicators of energy balance (protein content or body condition score) were positively associated with successful conception and pregnancy. This suggested a link between genetic merit for fat and protein content and lower ability of dairy cows to ensure pregnancy because of more nonfertilizations and early or late embryo mortality.

It was hypothesized that dimethyleacetamide (DMA) can be used as an alternate to glycerol for cryopreservation of Indian red jungle fowl semen. Four concentrations of DMA (4%, 6%, 8% and 10%) in extender were compared with previously optimized cryopreservation protocol based on 20% glycerol (control) for Indian red jungle fowl. Sperm motility, plasma membrane integrity, viability, and acrosome integrity were assessed at the stage of post-dilution, cooling, equilibration, and freeze-thawing. The whole experiment was repeated/replicated for five times independently. Sperm motility, plasma membrane integrity, viability and acrosome integrity were recorded highest (P < 0.05) at post-dilution, cooling, equilibration, and freeze-thawing in extender having 6% DMA compared to control and other experimental extenders. The highest (P < 0.05) recovery rates of all aforementioned parameters were also recorded in extender having 6% DMA; thus, 6% DMA was further compared with control (20% glycerol) for fertility after artificial insemination. Eggs were collected for five days after artificial insemination with semen cryopreserved in extender containing 6% DMA and control. The higher no. of fertilized eggs, fertility, no. of hatched eggs, hatch (%) and hatchability were recorded with semen cryopreserved in extender having 6% DMA compared to control. It is concluded that 6% DMA maintained higher post-thaw quality and fertility of Indian red jungle fowl semen and is a better replacement of glycerol. © 2017

L'étude des paramètres de reproduction des brebis Ouled Djellal (n=269), menée en semiintensif dans un milieu semi- aride, fait ressortir un taux de fertilité de 88 %, un taux de fécondité de 95 % et un taux de prolificité de 111 %. L'influence des différents facteurs sur les paramètres de reproduction, fait ressortir sur la fertilité, une influence significative (p

Meiosis in the tetraploid (2n = 80) males of Dioscorea alata L. was investigated for the first time. During metaphase I, the chromosomes were associated mostly in 6-8 quadrivalents and the remaining ones as bivalents with no trivalents or univalents. Anaphase I and subsequent stages of meiosis were normal. The observation of quadrivalents in the tetraploids provides cytological evidence for autotetraploidy. The autotetraploid males and females were highly fertile and they produced viable seeds on artificial pollination. Pollination between diploids (2n = 40) and tetraploids (2n = 80) were also successful via embryo rescue, producing triploid (2n = 60) progenies. The discovery of fertile autotetraploids could initiate polyploidy breeding in D. alata by conventional hybridization for the first time. The reduced number of quadrivalents and the high fertility of the autotetraploids are thought to be the result of partial diploidization of meiosis. The findings also refute the assumption of the allopolyploid origin of D. alata from two putative progenitors.

Sulfoxaflor is a novel insecticide belonging to sulfoximine chemical class that can be used to control sap-feeding insects, notably Aphis gossypii Glover. In addition to its acute toxicity, it is also important to consider the possible sublethal effects when establishing a comprehensive understanding of the toxicity of a new insecticide. We assessed the effects of a low lethal concentration (LC25) of sulfoxaflor on biological parameters of A. gossypii adults (F0) and subsequent transgenerational effects, i.e., on the progeny (F1 generation). The data were analyzed using an age-stage life table procedure. The results showed that the longevity and fecundity were not significantly affected by the LC25 of sulfoxaflor in the F0 or F1 generations. In addition, no significant differences were observed on the developmental time of each instar, the adult pre-oviposition period, and on the longevity of F1 individuals. However, the duration of their pre-adult stage and total pre-oviposition period, as well as their mean generation time were significantly increased. These observed effects affected aphid demographic traits; the survival rate, the intrinsic rate of increase (r (i) ), the finite rate of increase (lambda), the net reproductive rate (R-0), and the gross reproduction rate (GRR) of the F1 individuals (i.e., from F0 mothers) were significantly lower compared to the control. Our results showed that sublethal effects of sulfoxaflor significantly slowed down A. gossypii population growth; they indicated that effects of sulfoxaflor might be increased (beyond lethal effect) through sublethal effects when concentrations decreased in sulfoxaflor-treated areas after initial application in field.

International audience; Increasing temperature due to global warming has emerged one of the gravest threats to rice production. This study examined the influence of high temperature and exogenously applied plant growth regulators on pollen fertility, anther dehiscence, pollen germination and metabolites synthesis in pollens of two rice cultivars (IR-64 and Huanghuazhan (HHZ)). Plants were subjected to high day temperature (HDT), high night temperature (HNT) and control temperature (CT) in controlled growth chambers. Four different combinations of ascorbic acid (Vc), alpha-tocopherol (Ve), brassinosteroids (Br), methyl jasmonates (MeJA) and triazoles (Tr) were used along with a nothing applied control. Our results depicted that high temperature severely reduced the pollen fertility, anther dehiscence, pollen retention, germination and metabolites synthesis in pollens of both rice cultivars. Nonetheless, exogenous application of various plant growth regulators assuaged the adverse effects of high temperature and Vc + Ve + MeJA + Br was found the best combination than the other treatments for every studied characteristic. The HNT posed more negative effects than the HDT. Variations were also apparent between cultivars and HHZ performed better than IR-64 under high-temperature stress, with higher pollen fertility, better anther dehiscence, and greater pollen retention and germination rates. The greater tolerance of HHZ to high temperature was related with the higher synthesis of metabolites in this cultivar.

Nosema ceranae, a microsporidian parasite originally described in the Asian honey bee Apis cerana, has recently been found to be cross-infective and to also parasitize the European honey bee Apis mellifera. Since this discovery, many studies have attempted to characterize the impact of this parasite in A. mellifera honey bees. Nosema species can infect all colony members, workers, drones and queens, but the pathological effects of this microsporidium has been mainly investigated in workers, despite the prime importance of the queen, who monopolizes the reproduction and regulates the cohesion of the society via pheromones. We therefore analyzed the impact of N. ceranae on queen physiology. We found that infection by N. ceranae did not affect the fat body content (an indicator of energy stores) but did alter the vitellogenin titer (an indicator of fertility and longevity), the total antioxidant capacity and the queen mandibular pheromones, which surprisingly were all significantly increased in Nosema-infected queens. Thus, such physiological changes may impact queen health, leading to changes in pheromone production, that could explain Nosema-induced supersedure (queen replacement).

Dietary supplementation with propylene glycol (PG) increases in vitro production of high-quality embryos in feed-restricted heifers. The aim of the present study was to evaluate the effects of PG in feed-restricted heifers on follicular fluid insulin and insulin-like growth factor (IGF) 1 concentrations, expression of IGF system genes in oocytes and cumulus cells and the expression of selected genes in blastocysts. Feed-restricted (R) heifers were drenched with water or PG during induced oestrous cycles (400 mL of PG or water/drench, daily drenching at 1600 hours for the first 9 days of the oestrous cycle). Ovum pick-up (OPU) was performed after superovulation to produce in vitro embryos and without superovulation to recover oocytes, cumulus cells and follicular fluid. OPU was also performed in a control group (not feed restricted and no drenching). Follicular fluid IGF1 concentrations were reduced by R, and PG restored IGF1 concentrations to those seen in the control group. In cumulus cells, expression of IGF1, IGF1 receptor (IGF1R) and IGF binding protein 4 (IGFBP4) was decreased in the R group, and fully (IGF1 and IGF1R) or partially (IGFBP4) restored to control levels by PG. Blastocyst perilipin 2 (PLIN2; also known as adipophilin), Bcl-2-associated X protein (BAX), SCL2A1 (facilitated glucose/fructose transporter GLUT1), aquaporin 3 (AQP3), DNA (cytosine-5)-methyltransferase 3A (DNMT3A) and heat shock 70-kDa protein 9 (HSPA9B) expression were decreased in R heifers; PG restored the expression of the last four genes to control levels. In conclusion, these results suggest that, during follicular growth, PG exerts epigenetic regulatory effects on gene expression in blastocyst stage embryos.

The reproductive performance of two O. aureus pseudofemale groups was studied in three successive breeding seasons. At the end of the first breeding season, the two initial groups of pseudofemales were divided in two new experimental groups, the first with pseudofemales spawning more than three spawns (HSR = High Spawning Rate pseudofemales), and the second with the other pseudofemales (LSR = Low Spawning Rate pseudofemales). In the first breeding season, the mean number of spawns was significantly higher with HSR pseudofemales (7.4 ± 2.7 spawns pseudofemale − 1 ) than with LSR pseudofemales (0.7 ± 1.0 spawns pseudofemale − 1 ). The splitting up increased significantly the number of spawns in the both HSR (12.1 ± 3.7 spawns.pseudofemale − 1 ) and LSR (2.1 ± 3.1 spawns pseudofemale − 1 ) pseudofemales groups. The LSR pseudofemales stopped reproducing in the third breeding, season but not the HSR pseudofemales (7.1 ± 3.8 spawns pseudofemale − 1 ). The splitting up did not affect the high percentage (36.3%) of no-spawning pseudofemales detected during the first breeding season. During the second breeding season, the absolute (1024 ± 507 eggs spawn − 1 ) and relative (4433 ± 2233 eggs spawn − 1 kg − 1 ) fecundity of HSR pseudofemales were higher than those of LSR pseudofemales (791 ± 426 eggs spawn − 1 and 3177 ± 1617 eggs spawn − 1 kg − 1 , respectively). In the three successive breeding seasons, HSR pseudofemales produced 88.2% of spawns observed and 90.3% of eggs and fry collected. These data show that the reproductive potential in a group of O. aureus breeders depends on a few pseudofemales, those that have a high spawning capacity and a wide capacity of eggs production. This result suggests a scope to improve the spawning capacity in a line by studying the heritability of this reproductive trait in the successive generations of HSR breeders.

Spermiogenesis is a complex process leading to the formation of motile spermatozoa characterized by a highly stable chromatin compaction that transfers the paternal genome into the oocyte. It is commonly held that these haploid cells are devoid of transcriptional and translational activities and that the transcripts represent remnants of stored mRNAs. Recently, the chromatin organization of mature spermatozoa has been revisited as a double nucleoprotamine-nucleohistone structure possessing less-condensed regions sensitive to nuclease activity, which could be implicated in the expression of genes involved in the early embryo development. The existence of a complex population of mRNAs in human sperm is well-documented, but their role is not yet elucidated. Evidence for a latent transcriptional capacity and/or a potential de novo translation in mature spermatozoa from fertile men are essential for understanding the last steps of sperm maturation, such as capacitation and acrosome reaction. As such, we have documented the relationship between sperm quality and the distribution of sperm RNAs by showing divergent levels of transcripts encoding for proteins involved in either nuclear condensation (protamines 1 and 2) or in capacitation (eNOS and nNOS, c-myc) or in motility and sperm survival (aromatase) between low and high motile sperm issued from the same sample. Therefore, analyzing the profile of mRNAs could be helpful either as a diagnostic tool for evaluating male fertility after spermatogenesis or for prognosis use for fertilization.

Fertility is a major concern in the dairy cattle industry and has been the subject of numerous studies over the past 20 years. Surprisingly, most of these studies focused on rough female phenotypes and, despite their important role in reproductive success, male- and embryo-related traits have been poorly investigated. In recent years, the rapid and important evolution of technologies in genetic research has led to the development of genomic selection. The generalisation of this method in combination with the achievements of the AI industry have led to the constitution of large databases of genotyping and sequencing data, as well as refined phenotypes and pedigree records. These resources offer unprecedented opportunities in terms of fundamental and applied research. Here we present five such examples with a focus on reproduction-related traits: (1) detection of quantitative trait loci (QTL) for male fertility and semen quality traits; (2) detection of QTL for refined phenotypes associated with female fertility; (3) identification of recessive embryonic lethal mutations by depletion of homozygous haplotypes; (4) identification of recessive embryonic lethal mutations by mining whole-genome sequencing data; and (5) the contribution of high-density single nucleotide polymorphism chips, whole-genome sequencing and imputation to increasing the power of QTL detection methods and to the identification of causal variants.

The study was to focus on the relationship between wave motion (mass sperm motility, measured by a mass sperm motility score, manually assessed by artificial insemination (AI) center operators) and fertility in male sheep. A dataset of 711,562 artificial inseminations performed in seven breeds by five French AI centers during the 2001–2005 time period was used for the analysis. Factors influencing the outcome of the insemination, which is a binary response observed at lambing of either success (1) or failure (0), were studied using a joint model within each breed and AI center (eight separate analyses). The joint model is a multivariate model where all information related to the female, the male and the insemination process were included to improve the estimation of the factor effects. Results were consistent for all analyses. The male factors affecting AI results were the age of the ram and the mass motility. After correction for the other factors of variation, the lambing rate increased quasi linearly from three to more than ten points with the mass sperm motility score depending on the breed and the AI center. The consistency of the relationship for all breeds indicated that mass sperm motility is predictive of the fertility resulting when sperm are used from a specific ejaculate. Nonetheless, predictability could be improved if an objective measurement of mass sperm motility were available as a substitute for the subjective scoring currently in use in AI centers.

Introduction. Ricinodendron heudelotii Baill. est une essence forestiere en voie de domestication au Cameroun ou la plante est appreciee pour ses vertus alimentaires, ecologiques et medicinales. Les degâts causes par le psylle Diclidophlebia xuani Messi et al. aux jeunes plants, en pepiniere ou apres leur plantation, constituent l'une des principales contraintes a la domestication de l'espece. La biologie de ce ravageur a donc ete etudiee afin d'envisager son controle. Materiel et methodes. Differents aspects de la biologie de D. xuani ont ete abordes: processus d'accouplement, choix du site de ponte par la femelle, maturation sexuelle des imagos, fecondite des femelles, longevite des imagos, developpement embryonnaire et larvaire, sex-ratio a l'emergence et specificite alimentaire. Les experimentations ont eu lieu dans la region de Yaounde soit en champ, soit en milieu controle durant les annees 2001 et 2002. Resultats et discussion. Les mâles de D. xuani ont emerge avant les femelles et le rapprochement des sexes a eu lieu 15 min environ apres la mue imaginale. La longevite des femelles a ete de 29 jours en moyenne, celle des mâles, de 7 jours. La ponte a commence 3 jours apres l'emergence et s'est poursuivie jusqu'a la fin de la vie de la femelle. En periode chaude (28°C environ), une femelle a pondu en moyenne 532 oeufs pendant toute sa vie; en periode de basses temperatures (24°C a 26°C environ), la fecondite moyenne a ete de 758 oeufs. Les oeufs sont essentiellement deposes sur les etages foliaires les plus jeunes de R. heudelotii. Les developpements embryonnaire et larvaire ont dure respectivement 7 jours et 22 jours environ. Le cycle de developpement, d'oeuf a oeuf, a necessite 32 jours en moyenne. Le sex-ratio a ete proche de 1. Conclusion. D. xuani se developpe entierement et sans interruption sur R. heudelotii; il n'a jamais ete rencontre sur d'autres especes de plantes. Il serait donc etroitement associe a cette plante. (Resume d'auteur)

A seven-generation selection experiment comprising a selected (S) and a control (C) line was conducted with the objective of increasing the number of fertile eggs (F) of the Brown Tsaiya duck after a single artificial insemination (AI) with pooled Muscovy semen. Both lines consisted of about 20 males and 60 females since parents in each generation and each female duck was tested 3 times, at 26, 29 and 32 weeks of age. The fertile eggs were measured by candling at day 7 of incubation. The selection criterion in the S line was the BLUP animal model value for F. On average, 24.7% of the females and 15% of the males were selected. The direct responses to the selection for F, and correlated responses for the number of eggs set (Ie), the number of total dead embryos (M), the maximum duration of fertility (Dm) and the number of hatched mule ducklings (H) were measured by studying the differences across the generations of selection between the phenotypic value averages in the S and C lines. The predicted genetic responses were calculated by studying the differences between the S and C lines in averaged values of five traits of the BLUP animal model. The selection responses and the predicted responses showed similar trends. There was no genetic change for Ie. After seven generations of selection, the average selection responses per generation were 0.40, 0.33, 0.42, 0.41 genetic standard deviation units for F, M, Dm, and H respectively. Embryo viability was not impaired by this selection. For days 2–8 after AI, the fertility rates (F/Ie) were 89.2% and 63.8%, the hatchability rates (H/F) were 72.5% and 70.6%, and (H/Ie) were 64.7% and 45.1% in the S and C lines respectively. It was concluded that upward selection on the number of fertile eggs after a single AI with pooled Muscovy semen may be effective in ducks to increase the duration of the fertile period and the fertility and hatchability rates with AI once a week instead of twice a week.

Fertilization sensitivity to heat in rice is a major issue within climate change scenarios in the tropics. A panel of 167 indica landraces and improved varieties was phenotyped for spikelet sterility (SPKST) under 38°C during anthesis and for several secondary traits potentially affecting panicle micro-climate and thus the fertilization process. The panel was genotyped with an average density of one marker per 29 kb using genotyping by sequencing. Genome-wide association analyses (GWAS) were conducted using three methods based on single marker regression, haplotype regression and simultaneous fitting of all markers, respectively. Fourteen loci significantly associated with SPKST under at least two GWAS methods were detected. A large number of associations was also detected for the secondary traits. Analysis of co-localization of SPKST associated loci with QTLs detected in progenies of bi-parental crosses reported in the literature allowed to narrow -down the position of eight of those QTLs, including the most documented one, qHTSF4.1. Gene families underlying loci associated with SPKST corresponded to functions ranging from sensing abiotic stresses and regulating plant response, such as wall-associated kinases and heat shock proteins, to cell division and gametophyte development. Analysis of diversity at the vicinity of loci associated with SPKST within the rice three thousand genomes, revealed widespread distribution of the favourable alleles across O. sativa genetic groups. However, few accessions assembled the favourable alleles at all loci. Effective donors included the heat tolerant variety N22 and some Indian and Taiwanese varieties. These results provide a basis for breeding for heat tolerance during anthesis and for functional validation of major loci governing this trait.

International audience; Background: The impact of overweight among men of reproductive-age may affect fertility. Abdominal fat, more than body mass index, is an indicator of higher metabolic risk, which seems to be involved in decreasing sperm quality. This study aims to assess the relationship between abdominal fat and sperm DNA fragmentation and the effect of abdominal fat loss, among 6 men in subfertile couples. Methods: Sperm DNA fragmentation, abdominal fat and metabolic and hormonal profiles were measured in the 6 men before and after dietary advices. Seminal oxidative stress and antioxidant markers were determined. Results: After several months of a lifestyle program, all 6 men lost abdominal fat (patient 1: loss of 3 points of abdominal fat, patient 2: loss of 3 points, patient 3: loss of 2 points, patient 4: loss of 1 point, patient 5: loss of 4 points and patient 6: loss of 13 points). At the same time, their rate of sperm DNA fragmentation decreased: 9.5% vs 31%, 24% vs 43%, 18% vs 47%, 26.3% vs 66%, 25.4% vs 35% and 1.7% vs 25%. Also, an improvement in both metabolic (significant decrease in triglycerides and total cholesterol; p = 0.0139) and hormonal (significant increase in testosterone/oestradiol ratio; p = 0.0139) blood profiles was observed after following the lifestyle program. In seminal plasma, the amount of SOD2 has significantly increased (p = 0.0139) while in parallel carbonylated proteins have decreased. Furthermore, all spouses got pregnant. All pregnancies were brought to term. Conclusion: This study shows specifically that sperm DNA fragmentation among men in subfertile couples could be affected by abdominal fat, but improvement of lifestyle factor may correct this alteration. The effect of specific abdominal fat loss on sperm quality needs further investigation. The reduction of oxidative stress may be a contributing factor.

International audience; In winter oilseed rape (WOSR), only a subset of ovules can develop into seeds in the majority of pods. Any difficulty during the process of seed production may result in seed or pod abortion. This study aimed to reproduce the process of seed development in WOSR based on a limited number of parameters. As a result of the complexity of the developmental patterns of WOSR, it is challenging to identify the roles of various factors that influence seed production using an experimental approach. Here, we present a stochastic probabilistic model of seed development. The generalised least squares method was implemented to estimate the model parameters using the experimental data. Experiments were done in Grignon (France) in 2008 and 2009. The variations in the parameters were analysed according to the following four factors: year, pod rank, inflorescence position and ramification-clipping treatment. The year had no effect on the number of ovules per ovary (í µí¼‡) and the probability of seed viability (p). The proportion of effective pollen grains (k) significantly decreased with pod rank at the end of the main stem. Inflorescence position influenced the number of ovules per ovary (í µí¼‡: 30.8–33.8 from top to bottom) and the parameter k. The mean number of seeds per pod on the main stem and the bottom ramification along the stem was larger than the other ramifications within one plant. Ramification-clipping treatment increased the number of ovules per ovary (í µí¼‡: 31 for control plants and 32 for clipped plants), the parameter k and the number of seeds per pod (p). This effect could be due to the competition for assimilates between the pods and seeds. Furthermore, the distribution parameters of the pollen number per stigma (m) remained stable, and the probability of pod survival (Bo) varied with different factors, including the year, pod rank and inflorescence position. Our results indicate that pollen germination is a factor that determines final seed number. This model can identify the impact of each of the factors that lead to the abortion of seeds and pods in WOSR, which include the position effect, assimilate competition and pollination limitation. However, further studies on the pollination process in WOSR should help to refine this model.

International audience; A whole mount method was used to determine the moment of activation of oocyte growth in Varroa jacobsoni females. Ovaries of the mites were dissected and stained with toluidine blue. The coloration of the terminal oocyte indicates the uptake of euplasmatic and/or yolk material and, therefore, the initiation of the reproductive phase. In phoretic mites from adult bees, no staining of the ovary could be detected. V. jacobsoni females artificially introduced into freshly capped brood cells and removed for dissection 6 h later already showed clear blue staining of the terminal oocyte. The ovaries of V. jacobsoni females introduced 14 h after capping of the brood cell, however, remained uncolored after incubation in toluidine blue. We conclude that, in phoretic mites, oogenesis is arrested at a previtellogenic phase. Immediately after invasion of the brood cell, reproduction is activated by an as yet unknown host factor. This factor is present in freshly capped brood cells but not in brood cells 14 h after capping. Our new method offers new possibilities for the exact determination of oocyte growth and, therefore, for the study of V. jacobsoni fertility in different host and parasite populations.; Coloration au bleu de toluidine pour une détermination rapide du début de la croissance des ovocytes et de la fertilité chez Varroa jacobsoni Oud. La fertilité réduite des acariens Varroa jacobsoni dans les cellules de couvain d'ouvrières (Apis mellifera L.) est l'un des facteurs clés liés à la tolérance à la varroose, comme cela a été montré chez l'hôte d'origine Apis cerana Fabr. et chez les abeilles africanisées du Brésil. Les signaux qui déclenchent l'activation de la reproduction de l'acarien après l'invasion de la cellule de couvain restent à ce jour inconnus. Nous avons utilisé une nouvelle méthode de coloration in toto pour déterminer avec précision le début de la croissance des ovocytes. Des femelles phorétiques de V. jacobsoni ont été prélevées sur des abeilles adultes et introduites artificiellement dans des cellules de couvain fraîchement operculées et dans des cellules de couvain operculées depuis 14-16 h. Toutes les 6 h, les acariens ont été retirés des cellules et pesés sur une balance de précision. Immédiatement après la pesée, les ovaires ainsi que la spermathèque et l'organe en forme de lyre, ont été soigneusement disséqués, fixés dans la formaline à 4 % et colorés durant 30 min au bleu de toluidine à 0,005 % . Les ovocytes ont été lavés dans un tampon PBS et leur coloration a été analysée au microscope. La coloration de l'ovocyte dépend de l'incorporation de vitellus ou d'autres constituants euplasmatiques et marque donc l'activation de l'ovaire. Tous les acariens présents sur le couvain ont vu leur poids augmenter d'environ 325 $\mu$g à plus de 400 $\mu$g durant les 24 h qui ont suivi l'introduction (Fig. 1), quel que soit le moment de l'introduction. Ce comportement alimentaire indique une disposition générale des femelles phorétiques de V. jacobsoni à entrer dans la phase de reproduction. Mais chez tous les acariens phorétiques examinés (n = 18) aucune coloration au bleu de toluidine n'a été détectée (Tab. I ; Fig. 2a). Ceci confirme les observations antérieures selon lesquelles l'ovaire des acariens phorétiques est bloqué à un stade de prévitellogenèse. Pourtant, dans les ovaires des acariens présents sur le couvain, une coloration bleu clair de l'ovocyte terminal était déjà visible 6 h après l'introduction artificielle des acariens dans les cellules fraîchement operculées (n = 41 ; Tab. I ; Fig. 2b). Sur les 10 femelles de V. jacobsoni introduites 14 à 16 h après l'operculation, nous n'avons trouvé un ovocyte coloré que dans un seul ovaire (Tab. I), c'est-à-dire que, chez 90 % des acariens de ce groupe, la maturation des ovocytes n'avait pas commencé. En conclusion, la reproduction de V. jacobsoni doit être stimulée par un signal qui n'est présent que dans les cellules fraîchement operculées. Si les femelles de V. jacobsoni sont introduites dans des cellules operculées depuis 14 h, la croissance des ovocytes n'est pas du tout démarrée, ce qui indique l'absence de signal d'activation à ce stade de l'hôte. La nature du signal et les mécanismes de stimulation de la reproduction de V. jacobsoni restent inconnus. Notre nouvelle méthode offre la possibilité de déterminer avec précision la croissance des ovocytes dans de grands échantillons de femelles de V. jacobsoni. C'est donc un outil approprié pour des études en conditions semi-naturelles de la fertilité de V. jacobsoni dans des populations qui présentent divers degrés de tolérance à la varroose.

Coelaenomenodera lameensis Berti et Mariau (Coleoptera: Chrysomelidae, Hispinae), mineur des feuilles, est le principal ravageur du palmier a huile en Afrique. L'etude des variations, dans l'espace et dans le temps, de la fecondite a ete conduite sur 7 plantations de Cote d'Ivoire et sur 19 sites. Les fluctuations de la fecondite, qui peut varier de pres de 300 oeufs a quelques unites par periode de 90 jours, sont tres comparables sur divers sites d'une meme plantation ainsi que sur les sites de plantations differentes meme tres eloignees les unes des autres. La fecondite augmente avec la temperature mais d'autres parametres climatiques sont egalement importants, le deficit de saturation de l'air jouant un role determinant. Plus l'air est sec, plus la fecondite est faible, celle-ci pouvantdevenir presque nulle. Le degre de saturation de l'air ayant une grande action sur l'ouverture stomatique, on a pu etablir une correlation tres significative entre ce test et la fecondite. L'alimentation des larves et des adultes peut influer egalement sur la fecondite qui apparait etre tres variable en fonction de la teneur des feuilles en potassium. (Resume d'auteur)

Deux lignées de poules pondeuses ont été sélectionnées sur la consommation alimentaire résiduelle (+ R à consommation élevée, R- à faible consommation). Une détérioration des taux de fertilité et d’éclosion est observée dans la lignée R+. De nombreuses études réalisées sur les mammifères et les oiseaux ont montré l’association entre la mortalité embryonnaire et la présence d’anomalies chromosomiques. Dans le présent travail, des observations phénotypiques et des analyses cytogénétiques - limitées aux 10 premières paires de chromosomes observées et aux chromosomes sexuels, pour un total de 2n = 78 - ont été effectuées sur des embryons âgés de 48 ou de 16-18 h issus des 2 lignées R- et R+ aux générations 14 et 15. Des prélèvements de pulpes de plumes ont aussi permis de déterminer le caryotype de quelques adultes reproducteurs issus des 2 lignées. Le pourcentage d’oeufs clairs (non fécondés) est toujours significativement plus élevé en lignée R+. Les quelques cas d’anomalies chromosomiques mises en évidence dans les 2 lignées ne semblent pas être à l’origine de la baisse de fertilité de la lignée R+. Les reproducteurs adultes étudiés avaient tous des caryotypes normaux. L’explication de la baisse de fertilité en lignée R+ s’orienterait plutôt vers un problème de qualité des spermatozoïdes ou de leur conservation dans les voies génitales femelles dans la mesure ou l’étude cytogénétique n’a montré aucune anomalie de la méiose femelle ou de la multiplication des cellules embryonnaires. De plus les difficultés de reproduction ne sont pas concentrées dans certaines familles mais retrouvées dans toute la lignée., Two lines of brown egg layers have been divergently selected on residual food consumption (RFC). They differ markedly in their reproductive performance which deteriorates in the line selected on high values of RFC (R+ line). Several studies carried out in mammals and birds have shown a clear association between embryonic mortality and chromosomal abnormalities. In this study, fertile eggs were sampled from both lines at generations 14 and 15 after 48 or 16-18 h of incubation in order to observe the embryo development and determine the karyotype, on the first 10 pairs of chromosomes observed and sexual chromosomes, out of a total 2n = 78. Karyotypes were also prepared from feather pulps of adult breeders. The percentage of unfertilized eggs was always significantly higher in the R+ line. The few chromosomal abnormalities observed in both lines could not be responsible for the reduction in fertility in the R+ line. The adult karyotypes were normal. The lower fertility in the R+ line probably involves the quality of sperm cells or their conservation in the female genital tract, since cytogenetic analysis did not show any specific abnormality in female meiosis or in embryo cell multiplication. Furthermore, fertility problems were not clustered in some families but distributed over the entire line.

Background Sexual reproduction is common in eukaryotic microorganisms, with few species reproducing exclusively asexually. However, in some organisms, such as fungi, asexual reproduction alternates with episodic sexual reproduction events. Fungi are thus appropriate organisms for studies of the reasons for the selection of sexuality or clonality and of the mechanisms underlying this selection. Magnaporthe oryzae, an Ascomycete causing blast disease on rice, reproduces mostly asexually in natura. Sexual reproduction is possible in vitro and requires (i) two strains of opposite mating types including (ii) at least one female-fertile strain (i.e. a strain able to produce perithecia, the female organs in which meiosis occurs). Female-fertile strains are found only in limited areas of Asia, in which evidence for contemporary recombination has recently been obtained. We induced the forced evolution of four Chinese female-fertile strains in vitro by the weekly transfer of asexual spores (conidia) between Petri dishes. We aimed to determine whether female fertility was rapidly lost in the absence of sexual reproduction and whether this loss was controlled genetically or epigenetically. Results All the strains became female-sterile after 10 to 19 rounds of selection under asexual conditions. As no single-spore isolation was carried out, the observed decrease in the production of perithecia reflected the emergence and the invasion of female-sterile mutants. The female-sterile phenotype segregated in the offspring of crosses between female-sterile evolved strains and female-fertile wild-type strains. This segregation was maintained in the second generation in backcrosses. Female-sterile evolved strains were subjected to several stresses, but none induced the restoration of female fertility. This loss of fertility was therefore probably due to genetic rather than epigenetic mechanisms. In competition experiments, female-sterile mutants produced similar numbers of viable conidia to wild-type strains, but released them more efficiently. This advantage may account for the invasion of our populations by female-sterile mutants. Conclusions We show for the first time that, in the absence of sexual reproduction, female-sterile mutants of M. oryzae rice strains can arise and increase in abundance in asexual generations. This change in phenotype was frequent and probably caused by mutation. These results suggest that female fertility may have been lost rapidly during the dispersion of the fungus from Asia to the rest of the world.

Bu çalışmanın amacı Burdur ilindeki Repeat Breeding (RB) sütçü ineklerde Bovine Herpesvirus-1 (BHV-1) enfeksiyonunun seroprevalansını tespit etmek ve fertilite ile ilişkisini araştırmaktır. Çalışmada 108 RB sütçü inekten kan serumu toplandı ve BHV-1’e karşı şekillenen antikorlar yönünden enzyme linked immunosorbent assay (ELISA) ile test yapıldı. BHV-1 in prevalansı RB sütçü ineklerde %9.25 (10/108) olarak tespit edildi. Ortalama servis periyodu (SP) BHV-1 seropositive RB ineklerde, BHV-1 seronegative RB ineklerden istatistiksel olarak daha uzun (P

Hybrid vigour may help overcome the negative effects of climate change in rice. A popular rice hybrid (IR75217H), a heat-tolerant check (N22), and a mega-variety (IR64) were tested for tolerance of seed-set and grain quality to high-temperature stress at anthesis at ambient and elevated [CO(2)]. Under an ambient air temperature of 29 °C (tissue temperature 28.3 °C), elevated [CO(2)] increased vegetative and reproductive growth, including seed yield in all three genotypes. Seed-set was reduced by high temperature in all three genotypes, with the hybrid and IR64 equally affected and twice as sensitive as the tolerant cultivar N22. No interaction occurred between temperature and [CO(2)] for seed-set. The hybrid had significantly more anthesed spikelets at all temperatures than IR64 and at 29 °C this resulted in a large yield advantage. At 35 °C (tissue temperature 32.9 °C) the hybrid had a higher seed yield than IR64 due to the higher spikelet number, but at 38 °C (tissue temperature 34-35 °C) there was no yield advantage. Grain gel consistency in the hybrid and IR64 was reduced by high temperatures only at elevated [CO(2)], while the percentage of broken grains increased from 10% at 29 °C to 35% at 38 °C in the hybrid. It is concluded that seed-set of hybrids is susceptible to short episodes of high temperature during anthesis, but that at intermediate tissue temperatures of 32.9 °C higher spikelet number (yield potential) of the hybrid can compensate to some extent. If the heat tolerance from N22 or other tolerant donors could be transferred into hybrids, yield could be maintained under the higher temperatures predicted with climate change.

SummaryA significant decline in human male reproductive function has been reported for the past 20 years but the molecular mechanisms remain poorly understood. However, recent studies showed that the gap junction protein connexin-43 (CX43; also known as GJA1) might be involved. CX43 is the predominant testicular connexin (CX) in most species, including in humans. Alterations of its expression are associated with different forms of spermatogenic disorders and infertility. Men with impaired spermatogenesis often exhibit a reduction or loss of CX43 expression in germ cells (GCs) and Sertoli cells (SCs). Adult male transgenic mice with a conditional knockout (KO) of the Gja1 gene [referred to here as connexin-43 (Cx43)] in SCs (SCCx43KO) show a comparable testicular phenotype to humans and are infertile. To detect possible signaling pathways and molecular mechanisms leading to the testicular phenotype in adult SCCx43KO mice and to their failure to initiate spermatogenesis, the testicular gene expression of 8-day-old SCCx43KO and wild-type (WT) mice was compared. Microarray analysis revealed that 658 genes were significantly regulated in testes of SCCx43KO mice. Of these genes, 135 were upregulated, whereas 523 genes were downregulated. For selected genes the results of the microarray analysis were confirmed using quantitative real-time PCR and immunostaining. The majority of the downregulated genes are GC-specific and are essential for mitotic and meiotic progression of spermatogenesis, including Stra8, Dazl and members of the DM (dsx and map-3) gene family. Other altered genes can be associated with transcription, metabolism, cell migration and cytoskeleton organization. Our data show that deletion of Cx43 in SCs leads to multiple alterations of gene expression in prepubertal mice and primarily affects GCs. The candidate genes could represent helpful markers for investigators exploring human testicular biopsies from patients showing corresponding spermatogenic deficiencies and for studying the molecular mechanisms of human male sterility.

Une étude a été menée en laboratoire sur les inter-relations entre Nosema bordati Goudegnon et Apanteles flavipes (Cameron) lorsqu'ils parasitent simultanément Chilo partellus (Swinhoe). Il en ressort que N. bordati est très pathogène et virulente pour les stades immatures du parasitoïde. Faiblement infestés, les adultes peuvent disséminer la Microsporidie.

Deux lignées de poules pondeuses soumises à une sélection divergente sur la consommation alimentaire «résiduelle» (R+ à consommation élevée, R- à faible consommation) avaient montré antérieurement une différence des taux de fertilité et d’éclosion à l’avantage de R-. Dans le présent travail, elles ont été comparées pour la durée d’incubation (en 1987 et 1988) puis pour la réponse des taux de fertilité et d’éclosion à la durée de stockage des œufs avant la mise en incubation (en 1990). La durée d’incubation a été plus longue pour la lignée R+ que pour la lignée R-, d’environ 9 h et demie et 8 h en 1987 et 1988 respectivement. En 1990, on observe au total un désavantage hautement significatif des reproducteurs R+ pour le taux d’éclosion, ainsi qu’un effet dépressif de la durée de conservation des œufs sur le taux d’éclosion. Il n’y a pas d’interaction significative lignée x durée de stockage. Cependant, les données suggèrent une répartition quelque peu différente des causes de pertes à l’éclosion dans les 2 lignées, peut-être influencée par la durée du stockage., Two lines of laying hens submitted to a divergent selection for residual feed intake (+ R with high feed intake, R- with low feed intake) had previously shown differences for fertility and hatching rate to the advantage of R-. In the present work these lines have been compared for the duration of incubation (in 1987 and 1988), then for their response to the time during which eggs were kept before setting for incubation (in 1990). The duration of incubation was longer for the R+ line than for R- by ≈ 9.5 h and 8 h in 1987 and 1988 respectively. In 1990 on the whole, a highly significant disadvantage was found for the R+ line in hatchability, as well as a depressing effect of a longer storage of the eggs on hatchability. There was no significant line x storage duration interaction. However, the data suggest a some what different distribution of the causes of loss at hatching in the 2 lines, possibly influenced by the duration of egg storage.

A total of 416,670 lactations for 189,101 ewes from 3,603 sires and distributed across 1,978 herd-year groups were used to estimate genetic and environmental parameters of standardized milk yield (SMY(T)), fertility in ewe lambs (PR(1)), and fertility in adult ewes (PR(A)). Parameters were estimated with a multiple-trait sire linear model. Heritabilities for SMY(T), PR(1), and PR(A) were 0.27 (0.009), 0.04 (0.004), and 0.05 (0.004), respectively. These results were in accordance with the literature. The genetic correlation between PR(1) and PR(A) was 0.55, indicating that fertility is not the same trait in ewe lambs and adult ewes. The genetic correlation between milk yield and lamb fertility was not significantly different from zero. The genetic correlation between milk yield and fertility in adult ewe (-0.23) was in the range of antagonistic correlations reported in dairy cattle. Consequently, these results show that selection for milk yield can induce an indirect decrease in fertility. Nevertheless, no phenotypic decrease in fertility in artificial insemination matings has been observed in this population. This is the first time that correlation between milk yield and fertility is reported in sheep and further investigations are needed to confirm this result.

International audience; The objective was to identify postpartum risk factors between nutritional imbalance and health disorders affecting first-service conception risk (FSCR) in 21 commercial Holstein herds in Reunion Island. Multivariate logistic-regression models including herd as a random effect were used to analyze the relationship between FSCR and energy status, nitrogen status, hepatic function, mineral deficiencies, and postpartum health disorders. Two models (A and B) were built on two subsets of data (n = 446 and n = 863) with risk indicators measured during the first month of lactation and around time of first service, respectively, adjusted for season, breed, parity, origin, milk yield, calving to first service interval (CS1), and type of estrus (spontaneous vs. induced). The averaged conception risk was 0.266 +/- 0.015 (n = 913) (mean +/- S.E.M.). In both models, FSCR was decreased by CS1 < 60 d and induced estrus. In model A, FSCR was decreased ( p < 0.05) for cows with mean cumulative 100 d daily milk yield < 23 kg/d and >27 kg/d, with losses of body condition score >1.5, and with retained placenta. In model B, FSCR was decreased ( p < 0.05) for cows inseminated during wet season, previously raised out of the farm as nulliparous, with blood magnesium concentration 27 kg/d) with glutamate deshydrogenase > 17 UI/L. Hence, high-body-lipid mobilization during the first month of lactation was a strong nutritional predictor of low FSCR together with liver damage in high-yielding cows. Interestingly, our models revealed that infertility is better related to nutritional factors than to postpartum health disorders occurrence.

In phytophagous insects, life-history traits mainly depend on host plant range. Substantial longevity, high fecundity and larval competition are the major traits of polyphagous Tephritidae while species with a restricted host range generally exhibit a lower longevity and fecundity as well as mechanisms to avoid larval competition. Our aim in this study was to investigate the life history of an oligophagous species, the tomato fruit fly, Neoceratitis cyanescens (Bezzi). 2. We determined life tables under laboratory conditions in order to calculate the main demographic parameters of N. cyanescens and studied the influence of larval and adult diet on life-history traits. 3. The mean longevity of N. cyanescens females was 40 days. There was a strong synchronisation of female maturity. Oviposition showed an early peak at 9 - 13 days after a short pre-oviposition period (6 days). The absence of proteins in the adult diet both delayed ovarian maturation and decreased female fecundity. In addition, females originating from tomato fruits produced significantly more eggs than females originating from bugweed or black nightshade, showing that even the larval host plant may strongly affect the subsequent fecundity of adult females. 4. The traits of N. cyanescens are then discussed in the light of those documented for polyphagous and monophagous tephritids. Neoceratitis cyanescens displayed attributes intermediate between those of polyphagous and monophagous tephritids. Its smaller clutch size compared with polyphagous species and its specialisation on the Solanaceae family whose fruits contain toxic compounds may help in reducing intra- and inter- specific competition, respectively.

The mirid bug Sahlbergella singularis feeds on cocoa pods and shoots, causing considerable crop losses. As laboratory experimentation requires numerous insects, this study aimed at improving available rearing method of S. singularis for Cameroon. Fifty second to fifth nymphal stages were collected at a cocoa farm and reared to the adult stage on cocoa pods in an insectary (T = 24.7 � 0.9� C, RH = 84.5 � 6.8%, photoperiod: 12 : 12 L : D). Newly emerged females were confined for 5–6 days on cocoa twigs for sexual maturation and each female paired with a male for 24 h. The pairs were returned to the field and enclosed in mousseline sleeves on attached cocoa pods, for egg laying. After 16 days (expected egg lifetime), the sleeve cages were checked daily to detect newly hatched nymphs. Then, the pods were collected and brought to the insectary, where nymphs continued to emerge and develop into adults. Our method allowed the production of 14.6 � 6.7 nymphs per female per generation, for 15 consecutive generations. Nymphal survival was calculated to be 68.2% and the mean duration of the nymphal development was measured at 22.7 � 3.1 days. The rearing performance was evaluated using life-table calculations. The net reproductive rate (R0) was 6.59; the intrinsic rate of increase (r) was 0.037 per female per day with a population doubling time (Td )o f 18.9 days. On average each female contributed 9.70 individuals to the population given a mean generation time (Tc) of 52.1 days. The percentage of reproductive females and the mean number of nymphs per female were significantly different between generations, with 86.8% and 18.1% in generation G7 as compared to 45.8% and 8.4% for generation G5, respectively. As rainfall showed concordant variations during the period of investigation, we discuss the impact of this factor on mirid fecundity. J. Appl. Entomol.

Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699; International audience; Experiments were carried out to investigate the influence of combined nitrogen (N) and sulphur (S) fertility on the organosulphur compound content of garlic bulbs, especially alliin, as a specific flavour quality trait related to the health-value of garlic. Three cultivars, 'Printanor', 'Morasol' and 'Messidr6me', were grown in the greenhouse and in vitro. Sulphur was increased in the macronutrients within the range 0 - 144 mg l(-1). Numerous combinations of both S and N were tested in vitro. In the greenhouse, increasing N levels, from 184.8 mg l(-1) to 856.8 mg l(-1), were tested with a single high level of S (128 mg l(-1)). Increasing S alone did not affect the growth or bulb weight of any garlic cultivar, but slightly increased the alliin content of bulbs. No symptoms of S deficiency were observed under greenhouse conditions, although the same garlic cultivars grown in vitro at 0 mg S l(-1) clearly suffered, their size being greatly reduced. This suggests an important role for S contamination, such as atmospheric S, in the process of S absorption by garlic plants, which is discussed. Increasing N levels significantly accelerated garlic maturity and decreased bulb yield. The effect of N on the organosulphur compound content of bulbs was cultivar-dependent, but alliin accumulation was not enhanced. 'Printanor' and 'Morasol' had the highest alliin levels and were negatively influenced by increasing N, while a slight synergistic effect of S and N was observed on 'Messidrome'.'Messidrome' also had the highest flavour potential when including precursors, and was more efficient in accumulating S into organosulphur compounds. It is therefore advisable to choose the most appropriate variety, and to adapt the N x S fertilisation regime according to the environment, in order to produce garlic with the highest health-value.

The mammalian testis serves two main functions: production of spermatozoa and synthesis of steroids; among them estrogens are the end products obtained from the irreversible transformation of androgens by a microsomal enzymatic complex named aromatase. The aromatase is encoded by a single gene (cyp19) in humans which contains 18 exons, 9 of them being translated. In rats, the aromatase activity is mainly located in Sertoli cells of immature rats and then in Leydig cells of adult rats. We have demonstrated that germ cells represent an important source of estrogens: the amount of P450arom transcript is 3-fold higher in pachytene spermatocytes compared to gonocytes or round spermatids; conversely, aromatase activity is more intense in haploid cells. Male germ cells of mice, bank voles, bears, and monkeys express aromatase. In humans, we have shown the presence of a biologically active aromatase and of estrogen receptors (alpha and ss) in ejaculated spermatozoa and in immature germ cells in addition to Leydig cells. Moreover, we have demonstrated that the amount of P450arom transcripts is 30% lower in immotile than in motile spermatozoa. Alterations of spermatogenesis in terms of number and motility of spermatozoa have been described in men genetically deficient in aromatase. These last observations, together with our data showing a significant decrease of aromatase in immotile spermatozoa, suggest that aromatase could be involved in the acquisition of sperm motility. Thus, taking into account the widespread localization of aromatase and estrogen receptors in testicular cells, it is obvious that, besides gonadotrophins and androgens, estrogens produced locally should be considered to be physiologically relevant hormones involved in the regulation of spermatogenesis and spermiogenesis.

Fertility inheritance, a phenomenon in which an individual's number of offspring is positively correlated with his or her number of siblings, is a cultural process that can have a strong impact on genetic diversity. Until now, fertility inheritance has been detected primarily using genealogical databases. In this study, we develop a new method to infer fertility inheritance from genetic data in human populations. The method is based on the reconstruction of the gene genealogy of a sample of sequences from a given population and on the computation of the degree of imbalance in this genealogy. We show indeed that this level of imbalance increases with the level of fertility inheritance, and that other phenomena such as hidden population structure are unlikely to generate a signal of imbalance in the genealogy that would be confounded with fertility inheritance. By applying our method to mtDNA samples from 37 human populations, we show that matrilineal fertility inheritance is more frequent in hunter–gatherer populations than in food-producer populations. One possible explanation for this result is that in hunter–gatherer populations, individuals belonging to large kin networks may benefit from stronger social support and may be more likely to have a large number of offspring., Synopsis Fertility inheritance is a cultural trait that may strongly decrease the genetic diversity of a population. Fertility is said to be inherited when individuals belonging to large sibships are more likely to produce numerous offspring than are individuals with few siblings. Until now, fertility inheritance in humans has been investigated using genealogical data or a combination of genetic and demographic data. In this work, the authors propose a method of detecting fertility inheritance that is based on genetic data alone. Their method relies on the reconstruction of the gene genealogy of a sample of sequences and the computation of the degree of imbalance of that genealogy. Using mitochondrial data sampled in 37 human populations, they find that fertility inheritance is more common in hunter–gatherer populations than in food-producer populations. Thus, because the human population evolved under a hunter–gatherer regime until the Neolithic transition, fertility inheritance may be one of the factors explaining the relatively low genetic diversity of the human species.

Results on procedures for freezing stallion semen and the subsequent fertility during 20 years are presented. The present system applied in French National Stud includes: (1) a freezing protocol (dilution in milk, centrifugation and addition of freezing extender (INRA82 + egg yolk (2%, v/v) + glycerol (2.5%, v/v) at 22 °C, a moderate cooling rate to 4 °C and freezing at −60 °C/min in 0.5-ml straws); (2) selection of ejaculates showing post-thaw rapid motility >35%; and (3) an insemination protocol (mares examined once daily, two AI of 400 × 10 6 spermatozoa 24 h apart before ovulation, sufficient number of straws to have the possibility to perform six AI of 400 × 10 6 total spermatozoa, i.e. 2.4 × 10 9 total spermatozoa available per mare per season). This system was applied to >110 stallions per year, the average post-thaw motility of ejaculates was 50% (>1800 ejaculates) before selection. The semen freezability was defined as the number of selected ejaculates divided by the total number of ejaculates frozen. Of the stallions, 5, 4, 5, 21 and 64% had semen freezability of 0–10, 10–33, 33–60, 60–90 and over 90%, respectively. Per-cycle pregnancy rate was 45–48% (>1500 mares per year, 1.8 cycles per mare) and foaling rate 64%. In comparison, per-cycle pregnancy rate and foaling rate of mares hand-mated to stallions were 57–59% and 64%, respectively. The average number of straws used was 32–35 (1.75 × 10 9 total spermatozoa) per mare per season. According to our results and the literature, the most important factors for improving fertility of frozen equine semen include: (1) a low concentration of glycerol (2–3.5% final concentration); (2) a suitable base extender for freezing like Lactose–Glucose EDTA or INRA82; (3) a post-thaw motility >30–35%; and (4) a sufficient number of spermatozoa per mare per season (1.5–2 × 10 9 total spermatozoa for two to three cycles) divided into small units. Numbers of spermatozoa, lower than 750.10 6 total spermatozoa per cycle, could result in lower per-cycle pregnancy rate with higher additional costs for management of mares. Because there are no particular regulations on quality and quantity of equine semen in the European Community, there is a need for the uniformity of information about frozen semen. A codification is suggested, based on the number of spermatozoa available per mare per season, the post-thaw motility and the final glycerol concentration.

Five hundred and twenty-two isolates of Magnaporthe grisea isolated from rice in 5 Asian countries were characterized for their mating type by crossing them with 4 hermaphroditic isolates (KA3 and TH12: MAT1.1; Guy11 and TH 16: MAT 1.2). Among them, 41% were MAT 1.1 and 25% were MAT1.2. The remaining 34% did not produce perithecia with any of the 4 hermaphroditic testers. In Bangladesh, India, Nepal, Vietnam and in most provinces of China, both mating types were present. Only one mating type was found in 3 provinces and 1 city of China. Almost all the isolates had very low fertility, as they were in general female sterile and sometimes also male sterile. Hermaphroditic isolates were recovered from the 5 countries. In these countries, they represented between 13% and 75% of the isolates. In Zhejiang, Guizhou, Guangdong, Hunnan, Yunnan and Hubei provinces of China, hermaphroditic isolates represented between 6% and 67%. The genetic diversity of 143 isolates from these countries and provinces, where hermaphroditic isolates had been collected, was analyzed using SCAR markers. Genetic diversity was high and population structure did not resemble classical clonal structure described in most rice growing regions. The existence of sexual reproduction in the field, localization of a center of diversity in China, and migration between countries are discussed in this paper.

DOI:10.1051/gse:2002036; International audience; Organising the breeding plan of a seasonally breeding species, such as sheep, presents a challenge to farmers and the industry as a whole, since both economical and biological considerations need to be carefully balanced. Understanding the breeding activity of individual animals becomes a prerequisite for a successful breeding program. This study set out to investigate the sources of variation and the genetic profile of the spontaneous, out-of-season ovulatory activity of ewes of the Chios dairy sheep breed in Greece. The definition of the trait was based on blood progesterone levels, measured before exposing the ewes to rams, which marks the onset of the usual breeding season. Data were 707 records, taken over two consecutive years, of 435 ewes kept at the Agricultural Research Station of Chalkidiki in northern Greece. When all available pedigree was included, the total number of animals involved was 1068. On average, 29% of all ewes exhibited spontaneous, out-of-season ovulatory activity, with no substantial variation between the years. Significant sources of systematic variation were the ewe age and live weight, and the month of previous lambing. Older, heavier ewes, that had lambed early the previous autumn, exhibited more frequent activity. Heritability estimates were 0.216 ($\pm 0.084$) with a linear and 0.291 with a threshold model. The latter better accounts for the categorical nature of the trait. The linear model repeatability was 0.230 ($\pm 0.095$). The results obtained in this study support the notion that spontaneous out-of-season ovulatory activity can be considered in the development of a breeding plan for the Chios sheep breed.

Etude comparative de la secretion nectarifere et de l'attractivite vis-a-vis des abeilles de deux lignees de feverolle de printemps ( Vicia faba L var equina Steudel). Deux lignees de feverole de printemps tres proches genetiquement, l'une autofertile (D-27), l'autre peu autofertile (D-23), ont ete etudiees en conditions naturelles au champs pour leur nectar (production et composition) selon l'etat de la fleur et pour leur attractivite vis-a-vis de l'abeille mellifere (Apis mellifera L) et des bourdons (Bombus sp). Les deux lignees etudiees ont une production de nectar tres differente. La secretion de nectar de la lignee D-27 est en moyenne de 4 a 6 fois plus importante que celle de la lignee D-23 (tableau III) et c'est lorsque la fleur est ouverte que la production est optimale (fig 3). Les quantites recueillies apres 24 heures d'ensachage a 8, 10, 12, 16 h GMT sont de l'ordre de 1 a 2 μL par fleur. Certains jours, on detecte un effet heure et, dans ce cas, c'est le matin que la secretion est la plus abondante (8 h GMT). Les analyses realisees par la technique HPLC (chromatographie liquide haute performance) montrent que, parmi les sucres presents dans le nectar, le saccharose est nettement plus abondant que le glucose et le fructose. Les donnees presentent une grande variabilite tant entre plantes qu'entre genotypes (tableau V). Compte tenu de ces resultats (faible production entravant les analyses qualitatives et forte variabilite), une nouvelle methodologie est proposee pour comparer de maniere fiable les secretions entre les lignees. En ce qui concerne les abeilles melliferes, qui sont en majorite des butineuses de nectar, les deux lignees sont egalement attractives. En revanche, Bombus terres tris montre une nette preference pour D-27 (tableau VI), et il y pratique des trous de maniere a prelever le nectar sans penetrer dans la fleur des que celle-ci en secrete (stade fleur demi-fermee). Ces morsures ne modifient pas la secretion (tableau II). Que la fleur soit percee ou non, la proportion de visites negatives par ce bourdon est la meme sur les deux lignees (50 a 55 %). Dans nos conditions, les abeilles melliferes butineuses de nectar semblent utiliser assez peu les trous faits par les bourdons et 68,6 a 76,2 % d'entre elles effectuent des visites positives. Ceci implique qu'elle peuvent etre utilisees comme agent pollinisateur sur ces lignees. On peut penser que les faibles quantites de nectar produite par D-23 sont suffisantes pour attirer les abeilles. Cependant le fait que D-27, qui est autofertile (independante de la pollinisation entomophile) est la plus attractive pour les bourdons (tableau VI) est discute.

Over 500 independent transgenic rice plants have been obtained by the biolistic method with an average transformation frequency of 9.7% for japonica variety Taipei 309. A tight selection procedure using 50 mg/l of hygromycin B successfully prevented the growth of nontransformed tissues. Analysis of the T0 transgenic rice plants revealed that more than 97% of the transgenic plants were morphologically normal and more than 80% were at least partially fertile. The hygr trait was inherited as a dominant trait in a Mendelian manner in 8 out of 11 transgenic events assayed. Thirty-seven out of fifty transgenic plants were estimated to contain no more than five copies of the transgenes. In six out of seven transformation events, unlinked, co-transformed genes co-segregated in the T1 generation. The hygr trait has been stably inherited to the T4 generation. No chimerical transgenic plant has been found in an intensive search. Novel phenomena observed in transgenic rice plants are also reported.

Des haploïde-doublés (HD) de #Coffea canephora$ ont été développés en utilisant les embryons haploïdes qui apparaissent spontanément en association avec la polyembryonie. Les fréquences de graines polyembryonées et d'embryons haploïdes varient en fonction du génotype parental. Cependant la production d'un grand nombre de HD semble possible à partir de tous les génotypes. Plus de 750 HD produits à partir de différents génotypes ont été cultivés au champ et évalués pour plusieurs caractères agronomiques. Environ la moitié des génotypes HD n'ont pas survécu, suggérant un fort et négatif effet de l'homozygotie. La dépression de consanguinité est particulièrement sévère pour la vigueur végétative et les aspects liés à la reproduction. Pour plusieurs caractères tels que la forme des feuilles, la résistance à la rouille et le poids de 100 graines, une variation génétique considérable a été observée entre et à l'intérieur des groupes de génotypes HD constitués par les HD produits à partir d'un même clone. Malgré leur faible vigueur et fertilité réduite, les haploïde-doublés de #Coffea canephora$ offrent de nouvelles possibilités pour les études génétiques et l'amélioration des caféiers. (Résumé d'auteur)

Au Rwanda, 605 chèvres de race locale ont été inséminées sur oestrus induit par voie hormonale à partir d'un progestagène (FGA) imprégnant une éponge vaginale maintenue en place pendant 11 jours, associé à la PMSG et au cloprosténol injectés 48 h avant le retrait de l'éponge. Deux moments d'injection de la PMSG (48 h avant ou au retrait de l'éponge vaginale), deux doses de PMSG (200 ou 300 UI), et deux moments d'insémination (41 ou 45 h après le retrait de l'éponge), ont été testés. Les chèvres ont été inséminées par voie exocervicale une seule fois 41 ou 45 h après la fin du traitement progestatif avec une dose contenant 100 millions de spermatozoïdes conservés à l'état congelé. Le taux de fertilité moyen a été de 61,2 % (n = 605). Il a atteint 66,9 % pour 336 chèvres ayant reçu la PMSG 48 h avant le retrait de l'éponge vaginale. Le taux de prolificité, 2,14 en moyenne, a augmenté avec la dose de PMSG (200 UI : 2,05; 300 UI : 2,23; p < 0,05). Le taux de mortinatalité a été en moyenne de 13,3 % et était corrélé avec la prolificité (r = 0,91). Le passage à une dose de PMSG plus faible (100 UI) s'avère nécessaire pour réduire le taux de mortalité. Le moment d'insémination le plus favorable sera alors à déterminer.