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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.

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

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.

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 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.

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.

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; 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.

While available evidence supports the role of genetics in the pathogenesis of placental abruption (PA), PA-related placental genome variations and maternal-placental genetic interactions have not been investigated. Maternal blood and placental samples collected from participants in the Peruvian Abruptio Placentae Epidemiology study were genotyped using Illumina’s Cardio-Metabochip platform. We examined 118,782 genome-wide SNPs and 333 SNPs in 32 candidate genes from mitochondrial biogenesis and oxidative phosphorylation pathways in placental DNA from 280 PA cases and 244 controls. We assessed maternal-placental interactions in the candidate gene SNPS and two imprinted regions (IGF2/H19 and C19MC). Univariate and penalized logistic regression models were fit to estimate odds ratios. We examined the combined effect of multiple SNPs on PA risk using weighted genetic risk scores (WGRS) with repeated ten-fold cross-validations. A multinomial model was used to investigate maternal-placental genetic interactions. In placental genome-wide and candidate gene analyses, no SNP was significant after false discovery rate correction. The top genome-wide association study (GWAS) hits were rs544201, rs1484464 (CTNNA2), rs4149570 (TNFRSF1A) and rs13055470 (ZNRF3) (p-values: 1.11e-05 to 3.54e-05). The top 200 SNPs of the GWAS overrepresented genes involved in cell cycle, growth and proliferation. The top candidate gene hits were rs16949118 (COX10) and rs7609948 (THRB) (p-values: 6.00e-03 and 8.19e-03). Participants in the highest quartile of WGRS based on cross-validations using SNPs selected from the GWAS and candidate gene analyses had a 8.40-fold (95% CI: 5.8–12.56) and a 4.46-fold (95% CI: 2.94–6.72) higher odds of PA compared to participants in the lowest quartile. We found maternal-placental genetic interactions on PA risk for two SNPs in PPARG (chr3∶12313450 and chr3∶12412978) and maternal imprinting effects for multiple SNPs in the C19MC and IGF2/H19 regions. Variations in the placental genome and interactions between maternal-placental genetic variations may contribute to PA risk. Larger studies may help advance our understanding of PA pathogenesis. National Institutes of Health, the Eunice Kennedy Shriver National Institute of Child Health and Human Development (R01HD059827). National Heart Lung and Blood Institute (K01HL10374).

Sources of variation in measures of reproductive performance in dairy cattle were evaluated using data collected from 3207 lactations in 1570 cows in 50 herds from five geographic regions of Reunion Island (located off the east coast of Madagascar). Three continuously distributed reproductive parameters (intervals from calving-to-conception, calving-to-first-service and first-service-to-conception) were considered, along with one Binomial outcome (first-service-conception risk). Multilevel models which take into account the hierarchical nature of the data were used to fit all models. For the overall measure of calving-to-conception interval, 86% of the variation resided at the lactation level with only 7, 6 and 2% at the cow, herd and regional levels, respectively. The proportion of variance at the herd and cow levels were slightly higher for the calving-to-first-service interval (12 and 9%, respectively) — but for the other two parameters (first-service-conception risk and first-service-to-conception interval), >90% of the variation resided at the lactation level. For the three continuous dependent variables, comparison of results between models based on log-transformed data and Box–Cox-transformed data suggested that minor departures from the assumption of normality did not have a substantial effect on the variance estimates. For the Binomial dependent variable, five different estimation procedures (penalised quasi-likelihood, Markov-Chain Monte Carlo, parametric and non-parametric bootstrap estimates and maximum-likelihood) yielded substantially different results for the estimate of the cow-level variance.

Androgens and especially 11-oxygenated androgens are known to be potent masculinizing steroids in fish. As a first step to study their physiological implication in gonadal sex differentiation in fish, we cloned a testicular cytochrome P450(11beta) (11beta-hydroxylase) cDNA in the rainbow trout, Oncorhynchus mykiss. We isolated a 1882 bp P450(11beta) cDNA (rt11betaH2, AF217273) which contains an open reading frame encoding a 552 putative amino acids protein. This sequence was highly homologous (98% in nucleotides and 96.5% in amino acids) to another rainbow trout P450(11beta) sequence (AF179894) and also to a Japanese eel P450(11beta) (68% in amino acids). Northern blot analysis detected a single transcript of 2 kb which was highly expressed in the testis (stage II) and to a lesser degree in the anterior kidney (containing the interrenal tissue). No signal was detected in the posterior kidney, brain, liver, skin, intestine and heart. In the testis this transcript was highly expressed at the beginning of spermatogenesis (stages I and II), followed by a decrease during late spermatogenesis (stages III to V). By semi-quantitative reverse transcription polymerase chain reaction, P450(11beta) expression during gonadal differentiation was estimated to be at least 100 times higher in male than in female gonads. This difference was first detected at 55 days post-fertilization (dpf), i.e. 3 weeks before the first sign of histological sex differentiation, and was sustained long after differentiation (127 dpf). Specific P450(11beta) gene expression was also demonstrated before testis differentiation (around 50 dpf) using virtual Northern blot, with no expression detected in female differentiating gonads. From these results, and also based on the already known actions of 11-oxygenated androgens in testicular differentiation in fish, it is now suggested that P450(11beta) gene expression is a key factor for the testicular differentiation in rainbow trout.

The MMTV/neu transgenic (Tg) mice spontaneously develop mammary tumors stochastically after a long latent period, suggesting that the c-neu/erbB2 oncogene is not sufficient for tumor formation. To identify putative collaborator(s) of the c-neu/erbB2, we used the provirus insertional mutagenesis approach with mammary tumors arising in MMTV/neu Tg mice infected with the mouse mammary tumor virus (MMTV). The Notch1 gene was identified as a novel target for MMTV provirus insertional activation. In Notch1-rearranged tumors, the Notch1 gene was interrupted by the MMTV provirus insertion upstream of the exons coding for the TM domain. These insertions led to overexpression of novel 5' truncated approximately 7 kb RNA coding for 280 kDa mutant protein harboring only the Notch1 ectodomain, N(EC)mut. These may be involved in tumor formation. Another consequence of these insertions was the expression of truncated 3' Notch1 transcripts (3.5 - 4.5 kb) and proteins (86 - 110 kDa) deleted of most of the extracellular sequences (Notch1intra). We found that 3' truncated Notch1intra can transform HC11 mouse mammary epithelial cells in vitro. Deletion analysis revealed that the ankyrin-repeats and the domain 1 (aa 1751 - 1821) are required, while a signal peptide, the two conserved cysteines (C1652 and C1685) and the OPA and PEST sequences are dispensable for transformation. These results indicate that the N-terminally truncated Notch1intra protein behaves as an oncogene in this system.

Oestrogens and insulin-like growth factors (Igfs) play both a central role in the regulation of reproduction and growth and can interact especially in species showing a clear-cut sex-linked growth dimorphism (SGD) like in tilapia. Aromatase is essential in ovarian differentiation and oogenesis since it controls oestrogen synthesis. During tilapia sex differentiation, aromatase cyp19a1a expression increases from 9 days post-fertilization (dpf), resulting in high oestradiol level. High temperature, exogenous androgens or aromatase inhibitors override genetic sex differentiation inducing testes development through the suppression of cyp19a1a gene expression and aromatase activity. Supplementation with 17s-oestradiol (E2) of gonadectomized juveniles induced a sustained and higher E2 plasma level than in intact or gonadectomized controls and both sexes showed reduced growth. Juvenile and mature females treated with the aromatase inhibitor 1,4,6-androstatriene-3,17-dione had 19% lower E2 plasma level compared to controls and they showed a 32% increased growth after 28 days of treatment. Altogether, these data suggest that E2 inhibits female growth leading to the SGD. Regarding Igf-1, mRNA and peptide appeared in liver at ∼ 4 dpf and then in organs involved in growth and metabolism, indicating a role in early growth, metabolism and organogenesis. Gonad igf-1 showed an early expression and the peptide could be detected at ∼ 7 dpf in somatic cells. It appeared in germ cells at the onset of ovarian (29 dpf) and testicular (52 dpf) meiosis. In testis, Igf-1 together with steroids may regulate spermatogenesis whereas in ovary it participates in steroidogenesis regulation. Igf-1 and Igf-2 promote proliferation of follicular cells and oocyte maturation. Igf-3 expression is gonad specific and localized in the ovarian granulosa or testicular interstitial cells. In developing gonads igf-3 is up-regulated in males but down-regulated in females. In contrast, bream Gh injections increased igf-1 mRNA in male and female liver and ovaries but gonadal igf-3 was not affected. Thus, local Igf-1 and Igf-2 may play crucial roles in the formation, development and function of gonads while Igf-3 depending on the species is involved in male and female reproduction. Furthermore, precocious ethynylestradiol (EE) exposure induced lasting effects on growth, through pituitary gh inhibition, local suppression of igf-1 expression and in testis only down-regulation of igf-3 mRNA. In conclusion, SGD in tilapia may be driven through an inhibitory effect due to E2 synthesis in female and involving Igfs regulation.

The evolution of extravagant sexual traits by sensory exploitation occurs if males incidentally evolve features that stimulate females owing to a pre-existing environmental response that arose in the context of natural selection. The sensory exploitation process is thus expected to leave a specific genetic imprint, a pleiotropic control of the original environmental response and the novel sexual response in females. However, females may be subsequently selected to improve their discrimination of environmental and sexual stimuli. Accordingly, responses may have diverged and the original genetic architecture may have been modified. These possibilities may be considered by studying the genetic architecture of responses to male signals and to the environmental stimuli that were purportedly 'exploited' by those signals. However, no previous study has addressed the genetic control of sensory exploitation. We investigated this question in an acoustic pyralid moth, Achroia grisella, in which a male ultrasonic song attracts females and perception of ultrasound likely arose in the context of detecting predatory bats. We examined the genetic architecture of female response to bat echolocation signals and to male song via a cartographic study of quantitative trait loci (QTL) influencing these receiver traits. We found several QTL for both traits, but none of them were colocalized on the same chromosomes. These results indicate that - to the extent to which male A. grisella song originated by the process of sensory exploitation - some modification of the female responses occurred since the origin of the male signal. (Resume d'auteur)

Weekly milk records of 47 she-camels in a multibreed dairy camel herd were collected for over a period of 5 years. A total of 72 lactation curves were defined, and relationships with parity, calving season, lactation length, milk production level, following lactations, and dam weight were analyzed. Overall mean values were milk yield up to 12 months, 1,970 ± 790 l; lactation length, 12.5 months; persistency, 94.7 %; weekly peak yield, 50.7 l; monthly peak yield, 220 ± 90 l; and the number of weeks to reach peak yield, 28. The highest productivity was recorded in summer with a weekly mean of 48.2 ± 19.4 l, compared with 34.1 ± 16.3 l in winter. The highest average yield recorded was for camels at sixth parity, whereas the highest weekly peak was at eighth parity, and highest persistency at fifth parity. Camels that calved during the cold months (November to February) were most productives, with the highest persistency, peak yield, and longest lactation length. Four types of curves were identified corresponding to different parities and milk yield levels. Based on these data, specific models for camels are proposed.

In Madagascar, little information about drug residues in animal products is available. However, recently, official veterinary services were informed about the misuse of human injectable contraceptives in pig farms as an alternative for chirurgical castration of adult sows before culling. We investigated pigs (n = 80) slaughtered in 7 Malagasy abattoirs and raised in 8 of the 22 Malagasy regions (1) to confirm the contamination of carcasses by anabolic hormones by using LC-MS/MS, (2) to identify the substances of concern and (3) to explore the consumers' exposure to hormone residues. Medroxyprogesterone acetate was the only synthetic hormone detected in kidney fat. Samples positive with medroxyprogesterone acetate were observed in 66.7% of the districts investigated and in 87.5% of the surveyed regions, confirming its large misuse in livestock. Public awareness campaigns and control improvement among the animal production sector and among the Malagasy public health sector are therefore urgent.

Contact: baalassane_1981@yahoo.fr, moulinch@supagro.inra.fr; The herds of 95 families were monitored for 1 year in eight villages in the cotton-growing region of southern Mali. In 2006-2007, reproduction performances were average, with 0.54 calvings/year per cow, and mortality was low. Herd numerical productivity is not very high, less than 0.13/year, because of the high proportion of males kept for animal draught. Depending on the herd size, the behaviour of the families differs, in terms of off-take and in-take of animals. Families that only have one or two draught animals seek to increase their animal draught capacity, with a negative net off-take (-0.13/year). Families with two to three cows have a very low net off-take (0.02/year), with culling of adult animals compensated by purchase. They therefore capitalised this year, with an annual herd growth of 8%. Families with a very large herd (20 to 50 cows) take off more of their stock, with a net off-take of 0.08/year (very few animal purchases) and make a stock growth of 5%. And finally, families with an average-sized herd (6 to 19 cows) take off the whole of the year's production, with a net off-take of 0.11/year and a nil stock growth rate. The use of a demographic model made it possible to measure the sensitivity of the productivity rate to the different demographic parameters

Identification of the sex-determining genes of the Nile tilapia (Oreochromis niloticus) has important implications for commercial aquaculture. We previously identified an XX/XY sex-determining locus in this species within a 10-cM interval between markers GM201 and UNH995 on linkage group one (LG1). In order to refine this region, we developed new AFLP markers using bulked segregant analysis of the mapping families. We identified three AFLP markers that showed a sex-specific pattern of segregation. All three mapped near, but just outside, the previously identified sex-determining region on LG1. Hybridization of BAC clones containing these markers to chromosome spreads confirmed that the XX/XY sex-determining locus is on one of the small chromosomes in O. niloticus.

Recently, in addition to IGF-1 and IGF-2 the existence of a third form of IGF, termed IGF-3, limited to fishes, to be present only in the gonads and encoded by a separate gene has been reported. However, no further data have been presented on IGF-3. The present study on tilapia (Oreochromis niloticus) uses quantitative real-time PCR specific for tilapia IGF-1 and IGF-3. The organ distribution of IGF-3 mRNA in adult fish and the early ontogeny of IGF-3 in male and female gonads were studied. The potential sensitivity of IGF-3 to GH was revealed by intraperitoneal injections of bream GH using IGF-1 as control gene. The effects of 17alpha-ethinylestradiol (EE2) exerted after feeding of high EE2 doses and exposure to low environmentally relevant EE2 doses on IGF-3 expression in testis and ovary during early development were determined. Low IGF-3 mRNA expression levels were detected in most organs studied, with the highest extra-gonadal amount in the pituitary. During development, the IGF-3 gene was significantly upregulated in male but downregulated in female gonad. Injections of GH elevated IGF-1 mRNA in male and female liver and ovary. IGF-3 did not respond to GH treatment neither in ovary nor in testis. Both EE2 treatments resulted in significant downregulations of IGF-3 mRNA in testis while ovarian IGF-3 mRNA did not respond. Thus, IGF-3 may be involved in reproduction of fishes most likely in the male gonad only. Whether IGF-3 also has some physiological significance in ovary or other organs should be the topic of further studies.

Insulin-like growth factor (IGF)-I, which is crucially involved in fish growth, differentiation, and reproduction, occurs in tilapia pituitary. IGF-I peptide, which is probably produced in hypothalamic perikarya, is present in axons of the neurohypophysis, and IGF-I mRNA and peptide are present in the adenohypophysis in adrenocorticotrophic hormone cells, melanocyte-stimulating hormone cells, with interindividual differences in growth hormone cells, and, starting with puberty, in gonadotrophic hormone (GTH) cells. Subordinate males showed a high IGF-I but a lower beta-luteinizing hormone expression, while in dominant males the opposite was found. IGF-I from the GTH cells may act as auto/paracrine regulators of GTH cell proliferation and enhance GTH synthesis and release during puberty and reproduction, depending on the social status.

A 12-generation selection experiment involving a selected line (S) and a control line (C) has been conducted since 1992 with the aim of increasing the number of fertile eggs laid by the Brown Tsaiya duck after a single artificial insemination (AI) with pooled Muscovy semen. On average, 28.9% of the females and 17.05% of the males were selected. The selection responses and the predicted responses showed similar trends. The average predicted genetic responses per generation in genetic standard deviation units were 0.40 for the number of fertile eggs, 0.45 for the maximum duration of fertility, and 0.32 for the number of hatched mule ducklings' traits. The fertility rates for days 2–8 after AI were 89.14% in the S line and 61.46% in the C line. Embryo viability was not impaired by this selection. The largest increase in fertility rate per day after a single AI was observed from d5 to d11. In G12, the fertility rate in the selected line was 91% at d2, 94% at d3, 92% at days 3 and 4 then decreased to 81% at d8, 75% at d9, 58% at d10 and 42% at d11. In contrast, the fertility rate in the control line showed an abrupt decrease from d4 (74%). The same tendencies were observed for the evolution of hatchability according to the egg set rates. It was concluded that selection for the number of fertile eggs after a single AI with pooled Muscovy semen could effectively increase the duration of the fertile period in ducks and that research should now be focused on ways to improve the viability of the hybrid mule duck embryo.

This review deals with the complex sex determining system of Nile tilapia, Oreochromis niloticus, governed by the interactions between a genetic determination and the influence of temperature, shown in both domestic and wild populations. Naturally sex reversed individuals are strongly suggested in two wild populations. This can be due to the masculinising temperatures which some fry encounter during their sex differentiation period when they colonise shallow waters, and/or to the influence of minor genetic factors. Differences regarding a) thermal responsiveness of sex ratios between and within Nile tilapia populations, b) maternal and paternal effects on temperature dependent sex ratios and c) nearly identical results in offspring of repeated matings, demonstrate that thermosensitivity is under genetic control. Selection experiments to increase the thermosensitivity revealed high responses in the high and low sensitive lines. The high-line showed approximately 90% males after 2 generations of selection whereas the weakly sensitive line had 54% males. This is the first evidence that a surplus of males in temperature treated groups can be selected as a quantitative trait. Expression profiles of several genes (Cyp19a, Foxl2, Amh, Sox9a,b) from the gonad and brain were analysed to define temperature action on the sex determining/differentiating cascade in tilapia. The coexistence of GSD and TSD is discussed.

We identified DNA markers linked to sex determining genes in six closely related species of tilapiine fishes. The mode of sex determination differed among species. In Oreochromis karongae and Tilapia mariae the sex-determining locus is on linkage group (LG) 3 and the female is heterogametic (WZ-ZZ system). In O. niloticus and T. zillii the sex-determining locus is on LG1 and the male is heterogametic (XX-XY system). A more complex pattern was observed in O. aureus and O. mossambicus, in which markers on both LG1 and LG3 were associated with sex. We found evidence for sex-linked lethal effects on LG1, as well as interactions between loci in the two linkage groups. Comparison of genetic and physical maps demonstrated a broad region of recombination suppression harboring the sex-determining locus on LG3. Sex-specific recombination suppression was found in the female heterogametic sex. Sequence analysis showed the accumulation of repetitive elements in this region. Phylogenetic analysis suggests that at least two transitions in the mode of sex determination have occurred in this clade. This variation in sex determination mechanisms among closely related species makes tilapias an excellent model system for studying the evolution of sex chromosomes in vertebrates.

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.

Growth and sexual development are closely interlinked in fish; however, no reports exist on potential effects of estrogen on the GH/IGF-I-axis in developing fish. We investigate whether estrogen exposure during early development affects growth and the IGF-I system, both at the systemic and tissue level. Tilapia were fed from 10 to 40 days post fertilization (DPF) with 17α-ethinylestradiol (EE2). At 50, 75, 90, and 165 DPF, length, weight, sex ratio, serum IGF-I (RIA), pituitary GH mRNA and IGF-I, and estrogen receptor α (ERα) mRNA in liver, gonads, brain, and gills (real-time PCR) were determined and the results correlated to those of in situ hybridization for IGF-I. Developmental exposure to EE2 had persistent effects on sex ratio and growth. Serum IGF-I, hepatic IGF-I mRNA, and the number of IGF-I mRNA-containing hepatocytes were significantly decreased at 75 DPF, while liver ERα mRNA was significantly induced. At 75 DPF, a transient decline of IGF-I mRNA and a largely reduced number of IGF-I mRNA-containing neurons were observed in the female brain. In both sexes, pituitary GH mRNA was significantly suppressed. A transient downregulation of IGF-I mRNA occurred in ovaries (75 DPF) and testes (90 DPF). In agreement, in situ hybridization revealed less IGF-I mRNA signals in granulosa and germ cells. Our results show for the first time that developmental estrogen treatment impairs GH/IGF-I expression in fish, and that the effects persist. These long-lasting effects both seem to be exerted indirectly via inhibition of pituitary GH and directly by suppression of local IGF-I in organ-specific cells.

In the present study, we examined certain features of the functional anatomy of the female genital tract of the wild brush-tailed porcupine (Atherurus africanus) to obtain data on the reproductive biology of this African forest rodent. Two consecutive experiments were performed. The aim of the first was to establish macroscopic and microscopic features of the genital organs, and to explore correlations between predominant ovarian structures and vaginal contents in 20 wild, mature females. In the second experiment, we inspected the external genitalia and vaginal smears of a further 10 females in captivity on a daily basis for 90 days. The uterus of the brush-tailed porcupine is bicornuate and composed of two separated uterine horns, a uterine body and cervix. The genital tract does not present a vaginal vestibule. Thus, there is no portion common to genital and urinary tracts. Females in the follicular phase of the oestrous cycle showed increased cornification of the vaginal epithelium and a high density of eosinophilic cells in vaginal smears. The vulva and vaginal opening were open, reddish and tumefacted. In luteal phase or in pregnancy, epithelial cornification and eosinophilic features were notably reduced and the vagina presented a pale, non-tumefacted vulva and a vaginal closure membrane. Females in captivity showed spontaneous cycles, a polyoestrous reproduction pattern and, based on features of the external genitalia and vaginal smears, their oestrous cycle length was 27.1 ± 6.4 days (n = 12). (Resume d'auteur)

A selection experiment on maximum duration of fertility of Brown Tsaiya ducks after artificial insemination (AI) with pooled Muscovy semen has been conducted since 1992. The Brown Tsaiya ducks were divided into two lines: a control line (T) with no selection and a selected line (S). The traits measured were the number of eggs set that were laid from Days 2 to 15 after one AI (NES), the number of fertile eggs at candling (NEF), the total number of dead embryos (NED), the maximum duration of fertility (MD), and the number of hatched mule ducklings (NEH). The selected trait was NEF. Six generations with a total of 2,127 females were measured. The variance components were estimated for each line in a multiple-trait animal model, using the restricted maximum likelihood (REML) methodology, which yields estimates free of bias caused by selection and inbreeding. Estimates of the heritability and genetic correlation from the two lines were very similar. Heritabilities in the S and T lines, respectively, were 0.14 and 0.10 for NES, 0.30 and 0.26 for NEF, 0.06 and 0.09 for NED, 0.28 and 0.21 for MD, and 0.18 and 0.19 for NEH. High and favorable genetic correlations existed between NEF and MD (0.96 and 0.92), between NEF and NEH (0.86 and 0.91), and between MD and NEH (0.90 and 0.82). The results suggested that selection for NEF could improve the maximum duration of fertility, but it could be useful to check the estimates of genetic parameters in a meat-type female duck.

International audience; DMRT1 has been suggested to be the first conserved gene involved in sex differentiation found from invertebrates to human. To gain insight on its implication for fish gonadal differentiation, we cloned a DMRT1 homologue in the rainbow trout, Oncorhynchus mykiss (rtDMRT1), and showed that this gene is expressed during testicular differentiation, but not during ovarian differentiation. After 10 days of steroid treatment, expression was shown to be decreased in estrogen-treated male differentiating gonads but not to be restored in androgen-treated differentiating female gonads. This clearly reinforces the hypothesis of an important implication for DMRT1 in testicular differentiation in all vertebrates. In the adults a single 1.5 kb transcript was detected by Northern blot analysis in the testis, and its expression was found to be sustained throughout spermatogenesis and declined at the end of spermatogenesis (stage VI). Along with this expression in the testis we also detected by reverse transcriptase–polymerase chain reaction a slight expression in the ovary. We also obtained new DM-domain homologous sequences in fish, and their analysis suggest that at least four different genes bearing ‘DM-domain’ (DMRT genes) exist in fish just as in all vertebrate genomes.