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The biological quality of sterile male insects produced in a mass-rearing facility is a prerequisite for the success of the SIT, which is a component of area-wide integrated pest management (AW-IPM). Indeed, sterile male insects released in the field must have a good mating performance in order to compete with wild males, but they must also present the required level of sterility. In the present study, the biological quality of sterile male Glossina palpalis gambiensis produced in a mass-rearing insectary was assessed through quality control testing. The mating performance of irradiated males was assessed in walk-in field cages. Irradiation had no effect on adult emergence but significantly reduced the percentage of operational flies (from 89.58% to 79.87%) and male survival (from 5 to 4 days, on average). However, irradiation did not impact the sterile male insemination potential, with all females inseminated and more than 80% of the spermathecae completely filled. The rate of induced sterility in females was 89.67% due to a dose rate decrease of the radiation source. Moreover, sterile males were able to compete successfully with untreated fertile males for untreated females in walk-in field cages. This study confirmed that the flies were still competitive and stressed the importance of regularly checking the radiation source parameters.

When environmental conditions are unpredictable, expressing alternative phenotypes spreads the risk of failure, a mixed strategy called bet-hedging. In the southern part of its range, the Parsley Frog Pelodytes punctatus breeds both in autumn and in spring. Our aim was to study the breeding phenology and reproductive success associated with the use of those two seasonal niches to understand how this breeding strategy can be maintained. Field surveys revealed that breeding phenology was typically bimodal with a higher breeding effort in autumn. More importantly, in spring, the survival rate of offspring was severely reduced by the presence of autumn tadpoles, indicating a clear priority effect. However, the autumn cohort often failed to survive over winter, in which case spring cohorts were often successful. Based on those results, we constructed a model in which females can allocate a variable portion of eggs to each season and added a priority effect. We conclude that the existence of the two breeding seasons may indeed constitute a bet-hedging strategy.

International audience; Tsetse flies (Diptera: Glossinidae) are the main vectors of animal and human trypanosomoses in Africa. The Sterile Insect Technique (SIT) has proven effective in controlling tsetse flies when applied to isolated populations but necessitates the production of large numbers of sterile males. A new approach, called boosted SIT, combining SIT with the contamination of wild females by sterile males coated with biocides has been proposed for large-scale control of vector populations. The aim of the study was to evaluate this new approach using pyriproxyfen on the riverine species Glossina palpalis gambiensis (Vanderplank, 1949) in the laboratory. The contamination dose and persistence of pyriproxyfen on sterile males, the impact of pyriproxyfen on male survival, and the dynamics of pyriproxyfen transfer from a sterile male to a female during mating, as well as the impact of pyriproxyfen on pupal production and adult emergence, were evaluated in the laboratory. For this purpose, a method of treatment by impregnating sterile males with a powder containing 40% pyriproxyfen has been developed. The results showed that the pyriproxyfen has no impact on the survival of sterile males. pyriproxyfen persisted on sterile males for up to 10 days at a dose of 100 ng per fly. In addition, the horizontal transfer of pyriproxyfen from a treated sterile male to a female during mating could be measured with an average of 50 ng of pyriproxyfen transferred. After contacts without mating, the average quantity transferred was more than 10 ng. Finally, the pyriproxyfen powder was very effective on G. p. gambiensis leading to 0% emergence of the pupae produced by contaminated females. These promising results must be confirmed in the field. A large-scale assessment of this boosted pyriproxyfen-based SIT approach will be carried out against tsetse flies in Senegal (West Africa). On the African continent, tsetse flies (Diptera: Glossinidae) are the main vectors of the parasites responsible for Human African Trypanosomosis (HAT), or sleeping sickness, and Animal African Trypanosomosis (AAT), also called Nagana 1. These diseases caused by Trypanosomatidae belong to the group of neglected tropical diseases (NTDs), occurring in developing areas 2. Sub-Saharan African countries suffer from a significant impact of NTDs on public health and economic development 3. Glossina palpalis gambiensis (Vanderplank, 1949) is one of the main vectors of the HAT parasite in West Africa and is responsible for the persistence of many residual outbreaks of this disease in forest and savannah areas 4. There is still no vaccine against HAT and curative treatments are difficult to access for the most exposed and vulnerable populations 5. Glossina palpalis gambiensis is also involved in the transmission of AAT, which affects livestock and reduces animal production thus limiting the availability of food resources 6,7. Despite the millions of doses of trypanocides administered, nearly 3 million cattle die each year in Africa from AAT. Annual direct and indirect agricultural losses attributed to this disease are estimated at

The desert locust, Schistocerca gregaria, shows density-dependent reproductive trade-off by laying fewer but larger eggs in crowded conditions (gregarious phase) than in isolated conditions (solitarious phase). However, the physiological mechanisms controlling reproductive resource allocation remain unclear. We examined how egg production processes, including ovulation timing (i.e., oogenesis period), oocyte and ovarian growth rates, and oosorption rate (resorbing developing terminal oocytes), regulate reproductive outputs (egg biomass per clutch, egg size, and clutch size) during a reproductive cycle in S. gregaria by rearing them either under isolated or crowded conditions. We observed a common density-dependent negative correlation between egg size and clutch size, with no significant difference in egg biomass between the two rearing conditions. Dissection of female locusts after different days of oviposition revealed that the daily oocyte growth rate was almost similar between the two rearing conditions, but crowd-reared females ovulated later than isolated-reared ones, resulting in further oocyte growth in the former. Terminal oocytes were renewed by previous penultimate oocytes at the onset of a new reproductive cycle, and oosorption mainly occurred at an early stage in both rearing conditions; however, crowd-reared locusts displayed higher levels of oosorption compared to their isolated-reared counterparts. Crowding induced a high oosorption rate, resulting in a reduced clutch size and a prolonged oogenesis period, which in turn allowed oocytes to intake more yolk, which was probably recycled via oosorption. These results suggest that the length of the oogenesis period and oosorption rate are manipulated by maternal density, and these physiological modifications interactively regulate reproductive trade-off in S. gregaria.

SUMMARYA study was conducted to assess the awareness of cattle abortions due to brucellosis, Rift Valley fever (RVF) and leptospirosis, and to compare frequencies of reported abortions in communities living at the periphery of the Great Limpopo Transfrontier Conservation Area in southeastern Zimbabwe. Three study sites were selected based on the type of livestock–wildlife interface: porous livestock–wildlife interface (unrestricted); non-porous livestock–wildlife interface (restricted by fencing); and livestock–wildlife non-interface (totally absent or control). Respondents randomly selected from a list of potential cattle farmers (N = 379) distributed at porous (40·1%), non-interface (35·5%) and non-porous (26·4%), were interviewed using a combined close- and open-ended questionnaire. Focus group discussions were conducted with 10–12 members of each community. More abortions in the last 5 years were reported from the porous interface (52%) and a significantly higher per cent of respondents from the porous interface (P < 0·05) perceived wildlife as playing a role in livestock abortions compared with the other interface types. The odds of reporting abortions in cattle were higher in large herd sizes (odds ratio (OR) = 2·6; 95% confidence interval (CI) 1·5–4·3), porous (OR = 1·9; 95% CI 1·0–3·5) and non-porous interface (OR = 2·2; 95% CI 1·1–4·3) compared with livestock–wildlife non-interface areas. About 21·6% of the respondents knew brucellosis as a cause of abortion, compared with RVF (9·8%) and leptospirosis (3·7%). These results explain to some extent, the existence of human/wildlife conflict in the studied livestock–wildlife interface areas of Zimbabwe, which militates against biodiversity conservation efforts. The low awareness of zoonoses means the public is at risk of contracting some of these infections. Thus, further studies should focus on livestock–wildlife interface areas to assess if the increased rates of abortions reported in cattle may be due to exposure to wildlife or other factors. The government of Zimbabwe needs to launch educational programmes on public health awareness in these remote areas at the periphery of transfrontier conservation areas where livestock–wildlife interface exists to help mitigate the morbidity and mortality of people from some of the known zoonotic diseases.

Results of previous studies with different fish species, mostly from temperate- or cold-water habitats, indicate a species-specific diversity regarding the relationship between environmental temperature and values for sperm motility variables. In the current study, there was appraisal of environmental temperature effects on sperm motility of tilapia Oreochromis niloticus, a tropical fish species selected because of its aquaculture importance and capacity to reproduce in a broad range of water temperatures. Effects of environmental temperature on the spermatozoa motility characteristics were studied by temperature-controlled video-microscopy and CASA analysis at temperature range from 5 to 50 degrees C. It appeared that the Nile tilapia spermatozoa exhibit an unexpected capacity to express very different velocity characteristics over this temperature range. In the lower temperature range (5-10 degrees C), the percentage of motile cells was markedly variable among males. An abrupt increase in the linearity index was observed between 15 and 20 degrees C suggesting a physiological threshold in sperm movement at about 20 degrees C which is the minimum temperature for reproduction in the Nile tilapia. With faster spermatozoa velocity, there was a reduction of the motility duration at the greater temperatures. Initially, there is an increase in sperm velocity as the temperature increased until the maximal velocity occurred at 40 to 50 degrees C which is a temperature beyond that which occurs in natural spawning conditions. Results of the present study clearly indicate the importance of considering ambient temperature when charactering sperm motility and in determining optimal temperature conditions for fertilization in fish.

A better understanding of the factors affecting host plant use by spotted-wing drosophila (Drosophila suzukii) could aid in the development of efficient management tools and practices to control this pest. Here, proxies of both preference (maternal oviposition behavior) and performance (adult emergence) were evaluated for 12 different fruits in the form of purees. The effect of the chemical composition of the fruits on preference and performance traits was then estimated. We synthesized the literature to interpret our findings in the light of previous studies that measured oviposition preference and larval performance of D. suzukii. We show that fruit identity influences different parts of the life cycle, including oviposition preference under both choice and no-choice conditions, emergence rate, development time, and number of emerging adults. Blackcurrant was always among the most preferred fruit we used, while grape and tomato were the least preferred fruits. Larvae performed better in cranberry, raspberry, strawberry, and cherry than in the other fruits tested. We found that fruit chemical compounds can explain part of the effect of fruit on D. suzukii traits. In particular, oviposition preference under choice conditions was strongly influenced by fruit phosphorus content. In general, the consensus across studies is that raspberry, blackberry, and strawberry are among the best hosts while blackcurrant, grape and rose hips are poor hosts. Our results generally confirm this view but also suggest that oviposition preferences do not necessarily match larval performances. We discuss opportunities to use our results to develop new approaches for pest management.

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.

International audience; We characterised, for the first-time, the sound production of black-chinned tilapia Sarotherodon melanotheron and show differences with that of Nile tilapia Oreochromis niloticus in a hybridization pairing context. Although both species were able to produce drum sounds, they showed different acoustic features. Drum sounds were produced in aggressive (chasing or lateral attack) and non-aggressive (courtship) contexts by O. niloticus but only in aggressive situations (fleeing or avoidance) by S. melanotheron. The second type of sounds produced by O. niloticus were grunts, produced in both aggressive (chasing and after biting) and non-aggressive contexts (nest building). The second type of sound produced by S. melanotheron was a rolling sound, produced only during courtship. Each species was able to produce common sounds (drum) and species-specific sounds (grunts and rolling). This implies that species can communicate without being able to understand each other because the sounds emitted may probably have different significance. Drumming corresponded only to aggressivity in S. melanotheron, whereas this was not true for O. niloticus. 11-ketotestosterone (11-kt) levels were significantly higher in male O. niloticus than male S. melanotheron, but there was no significant correlation between 11-kt or estradiol concentrations and the number of sounds produced in aggressive or non-aggressive behavioural contexts in either species. During interspecies interactions, O. niloticus drum sounds are likely considered to be aggressive by S. melanotheron and could potentially constitute a reproductive barrier between the two species.

Egg-size adjustment is one of the important plastic life-history traits for animals living in heterogeneous environments. The adaptive investment hypothesis predicts that mothers should increase progeny size according to certain cues predicting adverse future conditions of their offspring. However, reproductive resources are limited, and females have to simultaneously reduce egg number to allocate more resources to increase size. It remains unclear how single individuals alter egg size and number according to temporally heterogeneous environments. In the present study, we examined how desert locusts, Schistocerca gregaria, plastically alter egg size and number according to population density. We also investigated the trans-generational maternal effects on progeny characteristics as well as their own maternal physiological response (oviposition interval). Females kept in crowded conditions laid significantly larger and heavier eggs by reducing clutch size (number of eggs per egg pod) compared to isolated females, suggesting the existence of a reproductive trade-off between the two traits. The crowding-forced isolated females induced concerted changes not only in egg size but also in egg number tending towards those characteristics of gregarious control, implying that single individuals showed trade-off when egg size was increased. Double-blind testing confirmed the rapid crowding effects on egg size. Females also responded to crowding by extending the oviposition interval. As the oviposition interval extended, egg size increased, but clutch size decreased. Eggs from crowding-forced isolated females began to produce gregarious-phase type hatchlings (large and black) instead of solitarious-phase type ones (small and green). These results suggested that S. gregaria plastically manipulate egg size by regulating egg numbers and egg production rate, and indicated the presence of trans-generational maternal effects on progeny phase.

Body weight, testes development and serum testosterone, follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels were determined and compared in two groups of peri-pubertal male dromedaries. Daily maximum and minimum ambient temperatures and dry and wet-bulb temperatures were recorded. Temperature-humidity index was calculated. The camels were divided into two equal groups of nine camels each, of comparable body weight: Group (A) received a diet of 13% crude protein and 2.9 MCal metabolizable energy (ME) with added premix, while Group (B) received a non-pelleted diet of alfa-alfa and wheat straw at the ratio of 1:3 giving 12.4% CP and 2.7 MCal ME. Individual feed intake was calculated after 14 days of adaptation. Feed offered and orts were recorded daily throughout the experimental period (24 months). Animals were fed diets containing 1:3 alfa alfa:wheat straw. Blood samples were collected from 5 camels in each group at 15-day intervals during the experimental period. None significant difference in total body weight was found between groups A and B throughout the entire experimental period (p >0.05). Group averages of daily feed intake for the entire period were 5.82 kg in group A and 7.08 kg in group B, respectively (p

Nile tilapia Oreochromis niloticus (NT) and Black-chinned tilapia Sarotherodon melanotheron (BCT) are respectively characterized by fast growth and water salinity tolerance which attract the farmers who could take advantage of both species characteristics by producing hybrids reared in brackish or marine waters. Little information is however available about social interactions between the two species which are distinct by their mode of parental care (oral incubation). The objective of this study was to determine the behaviour of the two species, NT and BCT placed in freshwater intraspecific and interspecific pairing contexts. Females of both species (n = 20 per species) were first isolated for 90 days in a 60 L aquarium to determine the average duration between spawning in the absence of males. With the approach of 4th spawning or after 90 days of isolation, intra and interspecific pairing (fish average weight 200.4 ± 5.1 g) were made 10 times by pairing mode in a 350 L aquarium. The day after fish pairing, 15 min videos were recorded at one hour intervals from 8:00 h to 17:00 h, and courtship and aggressiveness behaviour were quantified. The results showed that isolated NT females had an average duration between two spawning of 15.9 days. No spawning was observed in BCT females. Spawning events were observed in the NT intraspecific pairs, with strictly maternal oral egg incubations. Behavioural differences and some similarities were noted between the two species. NT male was the most dominant in front of females of both species and NT females showed dominance on BCT males. No clear hierarchy was observed in BCT pairs. Courtship behaviours were observed in all pairings with longer durations in NT pairs. Nest building was observed from 8:00 h to 17:00 h in both sexes of BCT and male NT. NT females built nests from 11:00 h with longer durations when paired with males BCT than when paired with their conspecific males. These first results, reflecting behavioural plasticity in both species suggested that other breeding conditions favouring less aggressive behaviour could lead to a natural interspecific hybridization between NT and BCT. (Resume d'auteur)

Colpodean ciliates potentially pose a problem to macro-organismic theories of evolution: they are putatively asexual and extremely ancient, and yet there is one apparently derived sexual species. If macro-organismic theories of evolution also broadly apply to microbial eukaryotes, though, then most or all of the colpodean ciliates should merely be secretively sexual. Here we show using de novo genome sequencing, that colpodean ciliates have the meiotic genes required for sex and these genes are under functional constraint. Along with these genomic data, we argue that these ciliates are sexual given the cytological observations of both micronuclei and macronuclei within their cells, and the behavioral observations of brief fusions as if the cells were mating. The challenge that colpodean ciliates pose is therefore not to evolutionary theory, but to our ability to induce microbial eukaryotic sex in the laboratory.Contact:dunthorn@rhrk.uni-kl.de

Tychoparthenogenesis, a form of asexual reproduction in which a small proportion of unfertilized eggs can hatch spontaneously, could be an intermediate evolutionary link in the transition from sexual to parthenogenetic reproduction. The lower fitness of tychoparthenogenetic offspring could be due to either developmental constraints or to inbreeding depression in more homozygous individuals. We tested the hypothesis that in populations where inbreeding depression has been purged, tychoparthenogenesis may be less costly. To assess this hypothesis, we compared the impact of inbreeding and parthenogenetic treatments on eight life‐history traits (five measuring inbreeding depression and three measuring inbreeding avoidance) in four laboratory populations of the desert locust, Schistocerca gregaria, with contrasted demographic histories. Overall, we found no clear relationship between the population history (illustrated by the levels of genetic diversity or inbreeding) and inbreeding depression, or between inbreeding depression and parthenogenetic capacity. First, there was a general lack of inbreeding depression in every population, except in two populations for two traits. This pattern could not be explained by the purging of inbreeding load in the studied populations. Second, we observed large differences between populations in their capacity to reproduce through tychoparthenogenesis. Only the oldest laboratory population successfully produced parthenogenetic offspring. However, the level of inbreeding depression did not explain the differences in parthenogenetic success between all studied populations. Differences in development constraints may arise driven by random and selective processes between populations.

Funding for Open Access provided by the UMD Libraries Open Access Publishing Fund., Background: Inversions and other structural polymorphisms often reduce the rate of recombination between sex chromosomes, making it impossible to fine map sex-determination loci using traditional genetic mapping techniques. Here we compare distantly related species of tilapia that each segregate an XY system of sex-determination on linkage group 1. We use whole genome sequencing to identify shared sex-patterned polymorphisms, which are candidates for the ancestral sex-determination mutation. Results: We found that Sarotherodon melanotheron segregates an XY system on LG1 in the same region identified in Oreochromis niloticus. Both species have higher densities of sex-patterned SNPs, as well as elevated number of ancestral copy number variants in this region when compared to the rest of the genome, but the pattern of differentiation along LG1 differs between species. The number of sex-patterned SNPs shared by the two species is small, but larger than expected by chance, suggesting that a novel Y-chromosome arose just before the divergence of the two species. We identified a shared sex-patterned SNP that alters a Gata4 binding site near Wilms tumor protein that might be responsible for sex-determination. Conclusions: Shared sex-patterned SNPs, insertions and deletions suggest an ancestral sex-determination system that is common to both S. melanotheron and O. niloticus. Functional analyses are needed to evaluate shared SNPs near candidate genes that might play a role in sex-determination of these species. Interspecific variation in the sex chromosomes of tilapia species provides an excellent model system for understanding the evolution of vertebrate sex chromosomes.

The genetic architecture of placental abruption (PA) remains poorly understood. We examined variations in SNPs of circadian clock-related genes in placenta with PA risk. We also explored placental and maternal genomic contributions to PA risk. Placental genomic DNA samples were isolated from 280 PA cases and 244 controls. Genotyping was performed using the Illumina Cardio-MetaboChip. We examined 116 SNPs in 13 genes known to moderate circadian rhythms. Logistic regression models were fit to estimate odds ratios (ORs). The combined effect of multiple SNPs on PA risk was estimated using a weighted genetic risk score. We examined independent and joint associations of wGRS derived from placental and maternal genomes with PA. Seven SNPs in five genes (ARNTL2, CRY2, DEC1, PER3 and RORA), in the placental genome, were associated with PA risk. Each copy of the minor allele (G) of a SNP in the RORA gene (rs2899663) was associated with a 30% reduced odds of PA (95% CI 0.52-0.95). The odds of PA increased with increasing placental-wGRS (Ptrend

International audience; Modeling the lactation curve is an important step for assessing the true milk potential of dairy animals. The present study aims to investigate the use of four different mathematical models (Wood, Cobby and Le Du,Cappio-Borlinoand and Dhanoa) to describe camel milk lactation curves, to estimate the potential of dairy she-camels and to identify different factors that could influence produced milk quantity and quality of Maghrebi she-camel. A total of 813 records from one experimental farm were used. Data collections were daily made with three milking per day. The complete milking was performed on two quarters (one posterior and one anterior). The other two were reserved for the calf and the volume collected was doubled. Among the four used mathematical models, the Wood model appeared the most appropriate according to mean square prediction error (MSPE), coefficient of determination (R2 = 83.56). The differences in estimated total milk yields between the models were not statistically significant. All models were adequate in describing total milk yield, although total milk yield estimated using the Wood model was very close to total milk yield. The quantities of daily produced milk differed among individuals. Milk production peaked approximately at 3rd months postpartum and then decreased. Daily production was 6.72 +/- 2.46 L. Milk yield decreased with lactation. Daily milking order as well as stage of lactation affects milk yield and its composition. These constituents became concentrated as lactation proceeded, and protein was substituted by fat. Calving date had a similar concentrating effect on fat whereas it decreased protein. This study showed that among the population of camels in Tunisia, improving environment and management of camel can be a way to improve milk production.

This study determined the prevalence of fetal wastage due to slaughter of pregnant camels, and the relationship between fetal wastage and factors such as breed, season, abattoir location, and age. Pregnancy characteristics of indigenous camels were also investigated. Reproductive tracts were collected from 912 female camels at two abattoirs in southeast Algeria over 2.5 years. Before slaughter, data regarding reasons for culling were obtained. Pregnancy was detected in 21.7% of camels and was higher (P

The present study aimed ta investigate the effect of nutrition on body weight gain, avaries development, blood components (total protein, alblllllen, globulin, cholesterol and glucose) and hormone level (estradiol and progesterone) in pre-pubertal she-camels. Fourteen dromedary she-camels (Camelus dromedarius) were divided in two groups CA and B) similar body weight and age ai the siart of the experiment (200 kg and 12 month, respectively). Group A received diet with 13% Crude Protein (CP) and 2.9 Meal Metabolisable Energy (ME). Group B received the traditional diet of the fann. Both diets contained 25:75 forage:concentrate. Individual feed intake was calculated after 14 days of adaptation period. Feed offered and arts was recorded daily during the whole experimental period of 12 months. Blood samples were taken from each group every 15 days throughout the experimental period. Estradiol, progesterone concentrations were measured using ELISA kits. Body weight and average daily gain for the Ist 6 months did not show significant differences between treatments. On the contrary for the last 6 months, treatment A significantly increased body weight and daily weight gain when compared to B (70.07±8.17 kg and 0.389±0.05 kg day-' vs. 37.86±8.17 kg and 0.210±O.05 kg day-l, respectively. Group A was more efficient converting feed to body weight comparing with group B. Feed Conversion Ratio (FCR) for the whole period was 11.25 and 13.74 for Group A and B, respectively. Group B had greater ovary size than Group A but the difference was not significant. Size of right ovary was smaller than the left one and season had positive effects on both right and left ovary sizes. Greater ovary sizes were observed in Winter and Spring comparing with Swnmer and Autumn. Group A had higher blood estradiollevel comparing with Group B while there was no difference between groups in progesterone levels. Il was concluded that feeding regirne did not affect body weight, daily body weight gain and blood progesterone levels but improved feed conversion ratio and blood estrogen levels. (Resume d'auteur)

L'évolution de la production de Pangasiidae depuis 15 ans en Asie du Sud-Est est celle d'une filière en pleine expansion. Le Vietnam offre l'exemple abouti d'une dynamique conjuguant progrès technique construit sur une recherche finalisée, évolution des systèmes de production et conquête de marchés à l'export. En Indonésie, sur les traces du Vietnam, l'élevage de ces poissons-chats se développe également depuis quelques années en vue d'alimenter les marchés domestiques et l'exportion. L'élevage des " pangas " au Vietnam est une activité traditionnelle. Pour sécuriser un système basé sur la capture d'alevins et de juvéniles dans le milieu naturel, un programme scientifique franco-vietnamien a été mis en place en 1993, visant à maîtriser la reproduction artificielle des deux principales espèces de pangas d'élevage, Pangasius bocourti (élevé en cages flottantes) et Pangasianodon hypophthalmus (élevé en étangs fertilisés). Obtenue avec succès en 1995, elle entraîna une profonde mutation de la filière. L'espèce utilisée pour les élevages en cages et destinée à l'exportation, P. bocourti, a révélé la difficulté de mener à terme sa maturation sexuelle en captivité et sa relativement faible fécondité. La seconde espèce a démontré, quant à elle, une bonne aptitude à la maturation en captivité et une fécondité dix fois supérieure. P. hypophthalmus est ainsi devenue la principale espèce d'élevage. Dans le même temps, l'évolution s'est faite vers une utilisation croissante de l'aliment industriel du fait d'une raréfaction du poisson de rebut, ingrédient stratégique de l'aliment artisanal vietnamien. Les coûts de production sont de 0,6-0,7 US$/kg (0,4-0,47 euro/kg) en moyenne. En Indonésie, l'élevage des pangas n'a véritablement démarré que dans les années 1990. Il est basé sur l'utilisation d'une espèce introduite, P. hypophthalmus, et d'une espèce locale, Pangasius djambal, élevées en étangs et en cages flottantes, en lacs ou en rivières, dans des exploitations le plus souvent familiales sur les îles de Java, Sumatra et Bornéo. Le Vietnam évalue sa production à 800 000 t en 2006 et prévoit une production de 1 000 000 t en 2007, en quasi totalité exportée. En Indonésie, la production reste plus modeste mais significative, avec 31 000 t en 2006.

Les taux annuels de mise bas et de mortalité sont des données de base nécessaires pour quantifier la productivité des cheptels domestiques tropicaux élevés en milieux extensifs. Les suivis de troupeaux avec bouclage des animaux sont une méthode de référence pour estimer ces paramètres sur le terrain. Les méthodes transversales rétrospectives, basées sur des entretiens avec les éleveurs et leur mémoire à court ou long terme de la démographie des troupeaux, sont des alternatives. La présente étude a évalué une méthode rétrospective (12MO) pour estimer les taux de mise bas et de mortalité pour la période des douze derniers mois précédents l'enquête. Le biais de différentes approximations utilisées dans les calculs a été évalué d'après plusieurs jeux de données disponibles et collectées sur les bovins et les petits ruminants au Sénégal. Le principal résultat de l'étude a été la variabilité potentiellement élevée du biais (en particulier pour le taux de mortalité des petits ruminants pour lequel le biais relatif a varié entre -60 et 96 p. 100 dans la classe d'âge " 0 à 1 an "), malgré un biais médian acceptable (la médiane de biais relatif a été inférieure ou égale à 6 p. 100 en valeur absolue). Les méthodes rétrospectives telles que 12MO devraient être utilisées avec parcimonie (par exemple pour évaluer approximativement l'impact immédiat de chocs importants ou d'innovations) et leurs résultats interprétés avec précaution. Lorsque cela est possible, les suivis de troupeaux (avec ou sans identification des animaux) sur plusieurs années consécutives devrait être privilégiés.

Environmental factors affect the sex ratio of many gonochoristic fish species. They can either determine sex or influence sex differentiation. Temperature is the most common environmental cue affecting sex but density, pH and hypoxia have also been shown to influence the sex ratio of fish species from very divergent orders. Differential growth or developmental rate is suggested to influence sex differentiation in sea bass. Studies in most fish species used domestic strains reared under controlled conditions. In tilapia and sea bass, domestic stocks and field-collected populations showed similar patterns of thermosensitivity under controlled conditions. Genetic variability of thermosensitivity is seen between populations but also between families within the same population. Furthermore, in the Nile tilapia progeny testing of wild male breeders has strongly suggested the existence of XX males in 2 different natural populations. Tilapia and Atlantic silverside studies have shown that temperature sensitivity is a heritable trait which can respond to directional (tilapia) or frequency dependent selection. In tilapia, transitional forms within a genetic sex determination (GSD) and environmental sex determination (ESD) continuum seem to exist. Temperature regulates the expression of the ovarian-aromatase cyp19a1 which is consistently inhibited in temperature masculinized gonads. Foxl2 issuppressed before cyp19a1. Recent in vitro studies have shown that foxl2 activates cyp19a1, suggesting that temperature acts directly on foxl2 or further upstream. Dmrt1 up-regulation is correlated with temperature-induced male phenotypes. Temperature through apoptosis or germ cell proliferation could be a critical threshold for male or female sex differentiation.

The aim of this study was to evaluate whether effects of environmental estrogens on fish growth and reproduction may be mediated via modulating the growth hormone (GH)/insulin-like growth factor I (IGF-I) system. To this end, developing male and female monosex populations of tilapia were exposed to 17alpha-ethinylestradiol (EE2) at 5 and 25 ng EE2/l water from 10-day postfertilization (DPF) until 100 DPF. Under exposure to both EE2 concentrations, sex ratio shifted toward more females and body length, and weight were significantly reduced in males. The growth-reducing effect was associated with significant changes in hepatic IGF-I expression, both in males and females and with significant alterations of IGF-I mRNA and GH mRNA in the brain. The changes in IGF-I and GH mRNA were accompanied by altered estrogen receptor alpha (ERalpha) expression in brain and liver. These findings point to an influence of estrogenic exposure on the endocrine GH/IGF-I axis. In addition, the EE2 treatment resulted in significant changes of ERalpha and IGF-I expression in ovaries and testis, suggesting that the estrogens interact not only with the endocrine but also with the autocrine/paracrine part of the IGF-I system. Overall, our results provide evidence that EE2 at environmentally relevant concentrations is able to interfere with the GH/IGF-I system in bony fish and that the impairing effects of estrogens reported on fish growth and reproductive functions may rather result from a cross talk between the sex steroid and the IGF-I system than be toxicological.

This study analyses reproductive parameters resulting from 74 parturitions in a population of captive collared peccaries in the eastern Amazon (Belém, State of Pará, Brazil) during a 65-month survey. Parturitions were homogeneously distributed throughout the year. The average litter size was 1.85 newborns per parturition. Collared peccary females had a newborn sex ratio of 52.6% females and 47.4% males. The mean age at first parturition was 639, although, the earliest first parturition occurred at age of 381 days. Estimated parturition-conception interval was 58 days. Mean farrowing interval was 196 days and mean production was 1.03 litters and 1.86 newborns per year per female. Mortality rate in newborns less than 2 months old was 26.9% of the total newborn population. Most identified causes of death were abandonment by the mother (22.2%) and trauma due to aggression (13.9%). Newborn deaths occurred mainly during the first two days of life. This study suggests that the collared peccary possesses interesting reproductive parameters for its introduction in captive breeding programmes in the Amazon region. © 2006 Published by Elsevier B.V.

International audience; Digital images from the left side of the mammary gland of 146 multiparous lactating dromedary camels in mid lactation and managed under intensive conditions were obtained immediately before milking and used to build up a reference scheme for the morphological evaluation of camel mammary glands. A 5-point linear scoring scheme (with 0.5-point accuracy) was subsequently generated based on five mammary traits (udder, depth and floor inclination, teats, shape, length, and width). Results showed that Arabian dairy camels had voluminous udders with large-sized teats. Most common udder shape was globular (47.3 %), followed by the pear (34.3 %) and pendulous (18.4 %) shapes. Conical- or funnel-shaped teats (60.9 %) were the most frequent, followed by cylindrical- (29.5 %) and blew-up (9.6 %)-shaped teats. The observed variation in the udder and teat measurements, as well as in typology, attested that dromedary camels need especially large milking clusters to improve their machine milkability. Assessment of the previously indicated digital images according to the proposed linear scoring scheme, performed by 3 independent operators showed that the overall means were close to 3.00 points (values between 2.45 and 3.62), and the standard deviations were close to 0.76 points (values between 0.58 and 0.94). Moderate repeatability between operators (r > 0.69) was obtained for udder depth and floor inclination, indicating that training of operators, as well as improvements in the definition of traits should be considered in future studies. Further research is needed to validate the proposed linear scoring system in different stages of lactation and parities using a large number of camels.

Introduction The circadian clock plays an important role in several aspects of female reproductive biology. Evidence linking circadian clock-related genes to pregnancy outcomes has been inconsistent. We sought to examine whether variations in single nucleotide polymorphisms (SNPs) of circadian clock genes are associated with PA risk. Methods Maternal blood samples were collected from 470 PA case and 473 controls. Genotyping was performed using the Illumina Cardio-MetaboChip platform. We examined 119 SNPs in 13 candidate genes known to control circadian rhythms (e.g., CRY2, ARNTL, and RORA). Univariate and penalized logistic regression models were fit to estimate odds ratios (ORs); and the combined effect of multiple SNPs on PA risk was estimated using a weighted genetic risk score (wGRS). Results A common SNP in the RORA gene (rs2899663) was associated with a 21% reduced odds of PA (P

International audience; Reproductive tract abnormalities have a high impact on sexual activity and fertility. Knowledge of factors related to reproductive disorders is important towards understanding the variability prevalences and features of these anomalies. The relationship between season, age, breed, and the body condition score, and the prevalence of reproductive abnormalities in female dromedary camels were analysed in an observational study on 740 dromedary females. Data were obtained from 2 abattoirs in southeast Algeria from 2011 to 2013. The associations between reproductive abnormalities and the different factors were determined using a chi-square test. Various abnormalities with different degrees of severity were observed in 213 (28.8%) cases. Reproductive abnormalities were significantly associated with age group and season. The percentages of reproductive abnormalities recorded did not differ significantly among breeds and abattoir location. The findings indicated a significant relationship between reproductive disorders and the body condition score. The prevalence of overall reproductive abnormalities significantly varied between the wet and dry seasons. Abnormalities were significantly more frequent during the wet seasons (autumn, winter) than during the dry-seasons (spring, summer). Based on these findings, the increased prevalence of reproductive disorders was associated with dry season, older age, and low body condition.

Energy allocation strategies have been widely documented in insects and were formalized in the context of the reproduction process by the terms ‘capital breeder’ and ‘income breeder’. We propose here the extension of this framework to dispersal ability, with the concepts of ‘capital disperser’ and ‘income disperser’, and explore the trade-off in resource allocation between dispersal and reproduction. We hypothesized that flight capacity was sex-dependent, due to a trade-off in energy allocation between dispersal and egg production in females. We usedMonochamus galloprovincialisas model organism, a long-lived beetle which is the European vector of the pine wood nematode. We estimated the flight capacity with a flight mill and used the number of mature eggs as a proxy for the investment in reproduction. We used the ratio between dry weights of the thorax and the abdomen to investigate the trade-off. The probability of flying increased with the adult weight at emergence, but was not dependent on insect age or sex. Flight distance increased with age in individuals but did not differ between sexes. It was also positively associated with energy allocation to thorax reserves, which increased with age. In females, the abdomen weight and the number of eggs also increase with age with no negative effect on flight capacity, indicating a lack of trade-off. This long-lived beetle has a complex strategy of energy allocation, being a ‘capital disperser’ in terms of flight ability, an ‘income disperser’ in terms of flight performance and an ‘income breeder’ in terms of egg production.

La stérilisation des espèces aquacoles est recherchée en aquaculture pour remédier aux problèmes de reproduction intempestive et risques de pollution génétique de la reproduction des poissons d'élevage échappés avec des espèces endémiques. Nous avons cherché à caractériser certains des mécanismes mis en jeu lors d'une stérilisation induite par de fortes températures chez une espèce de poissons thermosensible d'intérêt majeur en aquaculture, le tilapia du Nil, Oreochromis niloticus. L'effet d'une température élevée de 37°C sur le développement gonadique a été étudié pendant la différenciation sexuelle chez des alevins et pendant la maturation sexuelle chez des juvéniles, provenant de descendances mixtes (XXXY) et monosexes femelles (XX) /mâles (XY). L'analyse immunohistochimique de la protéine vasa montre que des traitements à 37°C provoquent une diminution du nombre de cellules germinales (CG) qui résulte d'une augmentation du taux d'apoptose et/ou d'une réduction du taux de prolifération de ces cellules, aboutissant à une stérilité partielle et transitoire ou complète et permanente. L'expression du gène vasa, marqueur des CG, est inhibée dans les gonades des poissons traités à 37°C pendant un minimum de 60 jours ; ceci est corrélé avec la réduction du nombre de CG dans ces gonades. La baisse du niveau d'expression des gènes cyp19a1a et amh, respectivement marqueurs de cellules somatiques femelles et mâles, suggère que la température de 37°C affecte également le nombre ou la fonctionnalité des cellules de la granulosa chez les femelles et de Sertoli chez les mâles. Un traitement de 60 jours est nécessaire pour induire de tels effets et semble impacter préférentiellement les gonades femelles. Ce travail confirme que les fortes températures induisent une réduction du nombre de CGs, en modifiant la balance entre les taux d'apoptose et de prolifération cellulaire, conduisant à des stérilités partielles ou totales.

The Notch signaling pathway is involved in a variety of developmental processes. Here, we characterize the phenotypes developing in the reproductive organs of male transgenic (Tg) mice constitutively expressing the activated mouse Notch1 intracellular domain (Notch1intra) under the regulatory control of the mouse mammary tumor virus (MMTV) long terminal repeat (LTR). Tg expression was detected in testis, vas deferens and epididymis by Northern blot analysis. In situ hybridization with a Notch1-specific probe lacked sensitivity to detect expression in normal-appearing cells, but demonstrated expression in hyperplastic epithelial cells of the vas deferens, epididymis and efferent ducts. Tg males from three independent founder lines were sterile. Histological analysis of reproductive organs of young Tg males (postnatal ages 8 and 21) showed no difference compared to those of non-Tg males. In contrast, in adult Tg mice from day 38 onwards, the efferent ducts, the vas deferens and most epididymal segments revealed bilateral epithelial cell hyperplasia with absence of fully differentiated epithelial cells. Electron microscopy confirmed the uniformly undifferentiated state of these cells. Immunohistochemistry with anti-PCNA antibody also revealed enhanced proliferation of Tg epididymis. In adult Tg testis, the different generations of germ cells of seminiferous tubules appeared normal, although some tubules were highly dilated and revealed an absence of early and/or late spermatids. The epithelial cells of the Tg tubuli recti and rete testis were not abnormal, but the rete testis was highly dilated and contained numerous spermatozoa, suggesting a downstream blockage. Consistent with a blockage of efferent ducts often seen at the rete testis/efferent duct interface, spermatozoa were absent in epididymis of all adult Tg mice and in all highly hyperplastic efferent duct tubules of these Tg mice. Such a blockage was visualized by injection of Evans blue dye into the rete testis lumen. Finally, the presence of ectopic hyperplastic efferent duct tubules was observed within the testicular parenchyma itself, outside their normal territory, suggesting that Notch1 signaling is involved in the establishment of these borders. This phenotype seems to represent a novel developmental defect in mammals. Together, these results show that constitutive Notch1 signaling significantly affects the development of male reproductive organs.

Evaluation of the Productivity of the Periurban Sheep at Maroua in the Far North of Cameroon. From 1995 to 1998, 1019 sheep belonging to about forty flocks within a radius of 0.5 - 10 km from Maroua centre were followed up. The main results show that in the various flocks females represent 70-80% of the population. The average litter size and annual reproduction rate are respectively 1.3 and 1.8 . The age at the first lambing is 16.5 ± 2.5 months. The average interval between two lambings is 251 ± 98 days. The average weight at the first lambing is 25 ± 3 kg and the average daily weight gain is equal to 66 ± 39 g. The flocks productivity calculated from a global index is equal to 702 ± 293 g of weaned lambs per kilogram of ewe per year. It varies inversely with the size of the flock. The high exploitation rate shows that the capitalisation is not the main objective of the periurban sheep owners and brings out the great importance of the sacrifice of tabaski or feast of the ram.

The brush-tailed porcupine Atherurus africanus is an important source of meat for local people in tropical forested areas of Central Africa. Information on the biology of this species in free-ranging conditions is scarce. Data on its reproduction and productivity are essential to establish accurate management practices in the exploitation of this rodent. In order to provide data on the reproductive physiology and to assess the prolificacy of the brush-tailed porcupine in the wild, the structural and functional anatomy of the ovaries of free-ranging females were studied. Twenty-two female carcasses were obtained from various markets in Libreville, Gabon, between August 1995 and February 1997. Reproductive tracts were macroscopically examined for the presence of embryos or foetuses. The ovaries were embedded in paraffin wax or plastic and examined by light microscopy. The morphology and constituent cell types of the ovaries were similar to those described for other hystricognath rodents. All pregnant females had only one embryo or foetus and the number of corpora lutea (CL) per female was 19.9 a 5.4 (mean diameter a sd, 1709 a 421 mm), including one CL of pregnancy (diameter, 4821 a 1364 mm). Also, 8.9 a 6.8 accessory CL per female in the pre-implantation and embryonic stages of pregnancy (diameter, 1629 a 463 mm) were observed. The average active luteal volume was high (115.6 a 73.5 mm 3 ). The mean number of antral follicles in the adult females was 24.6 a 9.9. The study confirms that the brush-tailed porcupine is a mono-embryonic species, as observed in captive breeding experiences, but polyovular, suggesting important ovum mortality. This unusual reproductive feature in a mammalian species gives this rodent a low reproductive productivity. Therefore, A. africanus could be more susceptible to the effects of hunting than generally thought.

International audience; In this study, we sought to determine the mechanism of early sex reversal in a teleost by applying 4hr feminization treatments to XY (17-ethynylestradiol 2000gL(-1)) and YY (6500gL(-1)) Nile tilapia embryos on the first day post-fertilization (dpf). We then searched for changes in the expression profiles of some sex-differentiating genes in the brain (cyp19a1b, foxl2, and amh) and in sex steroids (testosterone, 17-estradiol, and 11-ketotestosterone) concentrations during embryogenesis and gonad differentiation. No sex reversal was observed in YY individuals, whereas sex-reversal rates in XY progeny ranged from 0-60%. These results, together with the clearance profile of 17-ethynylestradiol, confirmed the existence of an early sensitive period for sex determination that encompasses embryonic and larval development and is active prior to any sign of gonad differentiation. Estrogen treatment induced elevated expression of cyp19a1b and higher testosterone and 17-estradiol concentrations at 4 dpf in both XY and YY individuals. foxl2 and amh were repressed at 4 dpf and their expression levels were not different between treated and control groups at 14 dpf, suggesting that foxl2 did not control cyp19a1b in the brains of tilapia embryos. Increased cyp19a1b expression in treated embryos could reflect early brain sexualization, although this difference alone cannot account for the observed sex reversal as the treatment was ineffective in YY individuals. The differential sensitivity of XY and YY genotypes to embryonic induced-feminization suggests that a sex determinant on the sex chromosomes, such as a Y repressor or an X activator, may influence sex reversal during the first steps of tilapia embryogenesis. Mol. Reprod. Dev. 81: 1146-1158, 2014. (c) 2014 Wiley Periodicals, Inc.