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Le parc de la Lékédi, ancien lieu de ranching touristique, souhaite aujourd’hui se reconvertir en aire de préservation de la biodiversité locale. Pour cela, il était nécessaire de réaliser un diagnostic de biodiversité afin de déterminer les enjeux de cette aire. Le travail réalisé a permis de démarrer ce diagnostic en s’intéressant au taxon des mammifères. L’étude réalisée a consisté en des relevés de faune pendant 1236 jours caméra, sur 36 emplacements répartis à travers les 14000ha du parc. Les résultats obtenus ont permis de valider la présence de 31 espèces de mammifères au sein du parc et de confirmer l’intérêt majeur qu’il présente pour la conservation des grands primates et de plusieurs autres espèces menacées. Cette étude a permis de poser les bases d’un examen méthodique du parc. Si les résultats obtenus sont déjà très encourageants, ils mettent aussi en lumière l’intérêt qu’il y aurait à examiner les autres taxons et à réaliser un suivi de longue durée, éventuellement ciblé sur les espèces à enjeux.

Prioritization of introduction pathways is seen as an important component of the management of biological invasions. We address whether established alien plants, mammals, freshwater fish and terrestrial invertebrates with known ecological impacts are associated with particular introduction pathways (release, escape, contaminant, stowaway, corridor and unaided). We used the information from the European alien species database DAISIE (www.europe-aliens.org) supplemented by the EASIN catalogue (European Alien Species Information Network), and expert knowledge. Plants introduced by the pathways release, corridor and unaided were disproportionately more likely to have ecological impacts than those introduced as contaminants. In contrast, impacts were not associated with particular introduction pathways for invertebrates, mammals or fish. Thus, while for plants management strategies should be targeted towards the appropriate pathways, for animals, management should focus on reducing the total number of taxa introduced, targeting those pathways responsible for high numbers of introductions. However, regardless of taxonomic group, having multiple introduction pathways increases the likelihood of the species having an ecological impact. This may simply reflect that species introduced by multiple pathways have high propagule pressure and so have a high probability of establishment. Clearly, patterns of invasion are determined by many interacting factors and management strategies should reflect this complexity

To fulfil the requirements for methionine, animal diets are widely supplemented with synthetic methionine sources such as L-methionine (L-Met), DL-methionine (DL-Met), and DL-2-hydroxy-4-(methylthio)-butanoic acid (DL-OH-Met). The objective of this study is to calculate the energy cost of the different conversion steps leading to L-Met and to propose energy equivalence values for DL-Met and DL-OH-Met, relative to that of L-Met. The conversion of DL-OH-Met to L-Met involves a nitrogen-sparing effect, because excess nitrogen can be used for the transformation of DL-OH-Met to L-Met, rather than being excreted as urea or uric acid Consequently, the ME-to-GE ratio of DL-OH-Met is 109% in mammals and 114% in birds, compared to the value of DL-Met. Because of differences in metabolism and the formation of hydrogen peroxide in the conversion to L-Met, the NE-to-ME ratios are 96% for DL-Met and 100% for DL-OH-Met in both mammals and birds. The conversion of DL-OH-Met to L-Met is therefore energetically less costly than the conversion of DL-Met. The stoichiometric approach presented here only considers the biochemical conversion steps, without considering the cost of transport and further transformation steps.

We present version 10 of OrthoMaM, a database of orthologous mammalian markers. OrthoMaM is already 11 years old and since the outset it has kept on improving, providing alignments and phylogenetic trees of high-quality computed with state-of-the-art methods on up-to-date data. The main contribution of this version is the increase in the number of taxa: 116 mammalian genomes for 14,509 one-to-one orthologous genes. This has been made possible by the combination of genomic data deposited in Ensembl complemented by additional good-quality genomes only available in NCBI. Version 10 users will benefit from pipeline improvements and a completely redesigned web-interface.

Methanogenic archaea occupy a functionally important niche in the gut microbial ecosystemof mammals. Our purpose was to quantitatively characterize the dynamics of methanogenesisby integrating microbiology, thermodynamics and mathematical modelling. For that, invitro growth experiments were performed with pure cultures of key methanogens from thehuman and ruminant gut, namely Methanobrevibacter smithii, Methanobrevibacter ruminantiumand Methanobacterium formicium. Microcalorimetric experiments were performed toquantify the methanogenesis heat flux. We constructed an energetic-based mathematicalmodel of methanogenesis. Our model captured efficiently the dynamics of methanogenesiswith average concordance correlation coefficients of 0.95 for CO2, 0.98 for H2 and 0.97 forCH4. Together, experimental data and model enabled us to quantify metabolism kineticsand energetic patterns that were specific and distinct for each species despite their use ofanalogous methane-producing pathways. Then, we tested in silico the interactions betweenthese methanogens under an in vivo simulation scenario using a theoretical modelling exercise.In silico simulations suggest that the classical competitive exclusion principle is inapplicableto gut ecosystems and that kinetic information alone cannot explain gut ecologicalaspects such as microbial coexistence. We suggest that ecological models of gut ecosystemsrequire the integration of microbial kinetics with nonlinear behaviours related to spatialand temporal variations taking place in mammalian guts. Our work provides novel informationon the thermodynamics and dynamics of methanogens. This understanding will beuseful to construct new gut models with enhanced prediction capabilities and could havepractical applications for promoting gut health in mammals and mitigating ruminant methaneemissions.

La maîtrise du moment de l’ovulation chez les mammifères d’élevage permet d’améliorer la fertilité, la gestion des mises bas, mais les méthodes actuelles sont basées sur l’utilisation de fortes doses d’hormones. Cette revue présente de nouveaux paradigmes pour maitriser le moment de l’ovulation, respectueux de la physiologie de l’animal, sans supplémentation hormonale basés sur la connaissance des mécanismes physiologiques.[br/] [br/] Le déclenchement de l’ovulation peut se faire selon deux modes chez les mammifères : spontané et provoqué. L’ovulation spontanée intervient au cours du cycle œstral sous l’effet de facteurs internes hormonaux. L’ovulation provoquée est déclenchée par l’accouplement avec un mâle. Dans les deux cas, c’est une augmentation de la sécrétion de GnRH qui conduit à l’augmentation de LH qui provoque l’ovulation. Les facteurs qui conduisent à l’augmentation de sécrétion de GnRH sont différents selon les deux modalités : principalement la kisspeptine (ovulation spontanée) et le b-NGF (ovulation provoquée). Les protocoles d’induction de l’ovulation actuels reposent sur une action directe sur l’ovaire, grâce à l’utilisation de gonadotropines hétérologues, ou bien par une action sur l’hypophyse grâce aux agonistes du GnRH. Ces protocoles présentent différents inconvénients : perte d’efficacité dans le temps, stimulation supra-physiologique qui peut être délétère, problème éthique posé par l’obtention de certaines molécules. De nouveaux paradigmes d’induction de l’ovulation ciblant l’hypothalamus, et favorisant un déclenchement physiologique de l’ovulation sans supplémentation en hormones sont en cours de développement. Cette revue a pour objectif de présenter au lecteur les mécanismes intimes impliqués dans la régulation et le déclenchement de l’ovulation ainsi que deux approches nouvelles respectueuses de la physiologie de l’animal et de l’environnement., The triggering of ovulation in mammals can be done according to two modes: spontaneous and provoked. Spontaneous ovulation occurs during the estrous cycle as a result of internal endocrine factors. Induced ovulation is triggered by mating. In both cases, it is the increase in GnRH secretion that leads to an increase in LH that causes ovulation. The factors involved in the stimulation of GnRH secretion are different according to the two modalities, mainly kisspeptin for spontaneous ovulators and beta-NGF for provoked ovulators. Current protocols used to induce ovulation rely on a direct action on the ovary, through the use of heterologous gonadotropins, or by an action on the pituitary gland with GnRH agonists. These protocols present different disadvantages: loss of activity with time, supra-physiological stimulation, ethic questioning about the production of some of these products. New paradigms for triggering ovulation by targeting the hypothalamus, respectful of animal welfare and the environment are presented in this review. This review aims to introduce the reader to the cellular and molecular mechanisms involved in the regulation and triggering of ovulation as well as two new approaches that are being developed and that are respectful of the animal and of its environment.

International audience; Chaperone-mediated autophagy (CMA) is a major pathway of lysosomal proteolysis essential for the control of intermediary metabolism. So far, the absence of any identifiable LAMP2A—a necessary and limiting protein for CMA—outside of the tetrapod clade, led to the paradigm that this cellular function was (presumably) restricted to mammals and birds. However, after we identified expressed sequences displaying high sequence homology with the mammalian LAMP2A in several fish species, our findings challenge that view and suggest that CMA likely appeared much earlier during evolution than initially thought. Hence, our results do not only shed an entirely new light on the evolution of CMA, but also bring new perspectives on the possible use of complementary genetic models, such as zebrafish or medaka for studying CMA function from a comparative angle/view.

International audience; Nanos are RNA-binding proteins playing crucial roles in germ cell development and maintenance.Based on phylogenetic and synteny analyses, this study reveals that nanos1 gene has undergonemultiple duplications and gene copies losses in Vertebrates. Chondrichthyan species display twonanos1 genes (named nanos1A/1B), which were both retrieved in some Osteichthyes at basal positionsin Sarcopterygii and Actinopterygii lineages. In contrast, Teleosts have lost nanos1A but duplicatednanos1B leading to the emergence of two ohnologs (nanos1Ba/1Bb), whereas Tetrapods have lostnanos1B gene. The two successive nanos gene duplications may result from the second and third wholegenome duplication events at the basis of Vertebrates and Teleosts respectively. The expression proflesof nanos1A and nanos1B paralogs were characterized in the dogfsh, Scyliorhinus canicula. Nanos1A wasstrongly expressed in brain and also localized in all germ cell types in the polarized testis. In contrast,nanos1B was detected in testis with the highest expression in the germinative zone. In addition,Nanos1B protein was predominantly located in the nuclei of male germinal cells. In the ovary, bothparalogs were detected in germinal and somatic cells. Our study opens new perspectives concerning thecomplex evolution of nanos1 paralogs and their potential distinct roles in Vertebrates gonads.

Supplemental information for this article can be found online at:http://dx.doi.org/10.7717/peerj.5534#supplemental-information; The family of forkhead box (Fox) transcription factors regulates gonadogenesis and embryogenesis, but the role of in reproduction is unknown. Evolutionary history of in vertebrates was examined and the gene was found to exist in most vertebrates, including mammals, ray-finned fish, amphibians, and sauropsids. By quantitative PCR and RNA-seq, we found that had an ovarian-specific expression in zebrafish, a common feature of maternal-effect genes. In addition, it was demonstrated using in situ hybridization that was a maternally-inherited transcript that was highly expressed even in early-stage oocytes and accumulated in the developing eggs during oogenesis. We also analyzed the function of in female reproduction using a zebrafish CRISPR/cas9 knockout model. It was observed that embryos from the -deficient females had a significantly lower survival rate whereby they either failed to undergo cell division or underwent abnormal division that culminated in growth arrest at around the mid-blastula transition and early death. These mutant-derived eggs contained dramatically increased levels of , a cell cycle inhibitor, and reduced , a component of mTOR and regulator of cell survival, which were in line with the observed growth arrest phenotype. Our study shows for the first time that is an essential maternal-effect gene and may be required for proper cell division and survival via the p21 and mTOR pathways. These novel findings will broaden our knowledge on the functions of specific maternal factors stored in the developing egg and the underlying mechanisms that contribute to reproductive success.

Modéliser les effets du changement climatique sur la biodiversité en région Nouvelle-Aquitaine nécessite des observations quantitatives sur l’abondance des espèces dans le temps et l’espace sur le terrain, afin d’obtenir des résultats significatifs. Des suivis protocolés sur le long terme ont ainsi été mis en place dans le cadre du programme les sentinelles du climat. Une vingtaine d’indicateurs biologiques sont suivis par type d’écosystème de 2016 à 2021. Ces suivis génèrent des milliers de données biologiques et des millions de données climatiques associés. Ce rapport présente la mise en place d’une réflexion de création d’une base de données spécifique. Cette base devient nécessaire pour : 1) gérer l’accumulation et la validation des informations, pour des analyses mécanistiques et statistiques dans le temps, dans le cadre du programme ; 2) permettre leurs exploitations pour la modélisation des répartitions spatio-temporelles des espèces actuelles et pour des projections dans différents scénarios de changement climatique ; 3) établir un état « 0 » répertorié, géré, analysé, diffusé dans l’objectif d’une comparaison d’état dans plusieurs décennies. L’outil de saisie proposé est à ce stade un gabarit standard de description des métadonnées et des données brutes des suivis naturalistes. Ce gabarit est associé à une base de fiches de terrain permettant de localiser précisément les unités d’échantillonnage.

International audience

Scientific reports 7, 44420 (2017). doi:10.1038/srep44420, Published by Nature Publishing Group, London

Après la découverte, au printemps 1991, par les deux associations spéléologiques du département, d’une accumulation d’ossements dans le réseau d’un système karstique, une opération de sauvetage urgent a été entreprise. L’opération avait pour but d’évaluer l’importance du gisement, de prélever en quantité des brèches fossilifères à différents niveaux du réseau et de mener une étude géologique détaillée pour comprendre les mécanismes de la mise en place de ce remplissage fossilifère. Le réseau ...

In mammals, the main olfactory system displays all the structural and functional characteristics at the last third of the gestational stage. Thus, the fetus is able to detect, to discriminate, but also to memorize the odorants present in the amniotic fluid in which it bathes. In the rodent, these odors memorized in utero are fundamental for the survival of the newborn at birth by allowing it to trend itself towards food sources. Afterwards, odorants are guiding the newborn to olfactory and food choices and are promoting subsequent learning. It is known that the mother's diet varies the olfactory keys of the biological fluids (amniotic fluid, milk) and thus modifies the nature of the olfactory sources encountered by the fetus and then the newborn in the perinatal period. The neuroanatomic and functional consequences of this impregnation are the subject of recent studies. The objective of this thesis was to characterize the effects of perinatal odor exposure on the maturation and functioning of the olfactory system in relation to the development of olfactory preferences and to a stressing challenge at weaning. For that, we set up a model of perinatal odor exposure through maternal feeding in the mI7-GFP murine transgenic strain expressing the olfactory receptor I7 coupled with the Green Fluorescent Protein (GFP). We evaluated the neuroanatomic, molecular and behavioral consequences on the pups before weaning, and their evolution over time by focusing our efforts on the postnatal stages 3 (PND3), PND12-14 and PND21. Due to the fragility of the transgenic strain, we worked on mI7-GFP mice pups crossfostered by CD1 mice mothers raised under the same conditions after having validated the presence of heptanal in the amniotic fluid of mI7-GFP mice and the milk of CD1 mice by GC-MSMS. We characterized the effects of perinatal odor exposure on the maturation and functioning of the olfactory system in relation to the olfactory preference until weaning (mI7-GFP mice pups under CD1 adoptive mothers) and on the stress reaction to maternal separation at weaning (CD1 mice pups under biological mother). Our results show that perinatal exposure to heptanal leads to a significant increase in the number of I7 glomeruli in the olfactory bulb (OB) associated to a slight modification of the tissue homeostasis in the olfactory mucosa (OM) and to subtle differencies in heptanal sensitivity and preferences, that are amplified at PND21. From a molecular point of view, these effects are associated to a down-regulation of the expression of the I7 receptor and genes of neuronal signaling and an odorantspecific decrease in EOG response which may highlight a modification of the cellular dynamics. Finally, the effect of perinatal exposure to heptanal on the response to stressing conditions after maternal separation was assessed by recording CD1 mice pups grown under the same conditions than fostered mi7 mice on odorized and non odorized open-field. We showed that the reaction of odorized mice in the open field at PND21 is attenuated when the odorant is present in the environment, compared to non odorized mice that display anxiety-like behavior. Overall, this study demonstrates the consequences of a perinatal odorant exposure in the young, in terms of behavior (olfactory preference and anxiety), structural and molecular plasticity of the olfactory system, on a transgenic strain for which we had little available data.; Chez les mammifères, le système olfactif principal est fonctionnel dans le dernier tiers du stade gestationnel. Le fœtus est donc capable de détecter avec sensibilité, discriminer, et mémoriser les odorants présents dans le liquide amniotique dans lequel il baigne. Chez le rongeur, ces odorants mémorisés in utero sont fondamentaux pour la survie du nouveau-né à la naissance en lui permettant de s’orienter vers la mamelle et de déclencher la tétée. Par la suite, ces odorants vont guider le nouveau-né dans ses choix olfactifs et alimentaires et favoriser ses apprentissages ultérieurs. Or, on sait que l’alimentation de la mère fait varier les clés olfactives des fluides biologiques (liquide amniotique, lait) et donc modifie la nature des sources olfactives rencontrées par le fœtus, puis le nouveau-né dans la période périnatale. Dans le but d’évaluer l’impact d’une exposition odorante périnatale sur le fonctionnement et la maturation du système olfactif en relation avec le développement de préférences médiées par l’olfaction et la modulation du stress au moment du sevrage, nous avons mis en place un modèle d’exposition odorante périnatale via l’alimentation maternelle dans une lignée transgénique murine exprimant le récepteur olfactif I7 couplé à une protéine fluorescente, dont l’odorant préférentiel est l’heptanal. Après validation de la présence d’heptanal dans le liquide amniotique et le lait de ces souris par GC-MS-MS, nos résultats montrent que l’exposition périnatale à l’heptanal entraine une augmentation significative du nombre de glomérules I7 présents au niveau du bulbe olfactif à PN12 par rapport aux animaux contrôles sans modification notable de l’homéostasie tissulaire ou de la transcription du gène I7 au niveau de la muqueuse olfactive. Ce changement structural important au niveau des projections axonales du bulbe olfactif s’accompagne d’un faible effet sur le comportement olfactif des souriceaux dont les capacités de discrimination ne sont que très faiblement améliorées par rapport aux souriceaux non exposés. A PN21, l’effet de l’exposition odorante sur le nombre de glomérules I7 est atténué, mais reste significatif. A ce stade, les souriceaux odorisés montrent une attraction olfactive pour l’heptanal par rapport au groupe contrôle non exposé, bien que l’effet sur un choix entre aliment odorisé ou pas soit plus contrasté. D’un point de vue moléculaire, ces effets sont associés à une diminution de l’expression du récepteur I7, et de gènes de la signalisation neuronale pouvant traduire une modification de la dynamique cellulaire. Et comme le montrent les résultats obtenus en électro-olfactogramme à cet âge, la sensibilité de la muqueuse olfactive vis-à-vis de l’heptanal est diminuée alors qu’elle ne l’est pas pour d’autres composés odorants. Ces travaux montrent que l’exposition périnatale à un odorant s’accompagne d’effets précoces sur le système olfactif qui impactent son organisation et d’effets sur les choix olfactifs qui se renforcent au cours du développement. Enfin, l’effet d’une exposition périnatale à l’heptanal sur la réponse à des conditions stressantes après séparation maternelle au moment du sevrage a été évaluée en enregistrant des souriceaux CD1 élevés dans les mêmes conditions d’odorisation que les souriceaux mI7-GFP adoptés, en open-field odorisé ou non. Nous avons montré que la réaction de stress des souriceaux à PN21, exposés en périnatal à l’heptanal, dans l’open field, est atténuée lorsque l’heptanal est présent dans l’environnement, comparé à la réaction des souriceaux non exposés qui affichent un comportement d’anxiété. Dans l’ensemble, cette étude a donc permis de mettre en évidence les conséquences en terme d’effets comportementaux (préférences médiées par l’olfaction et diminution du stress), structuraux et moléculaires, d’une exposition odorante périnatale chez le jeune, à l’aide d’une lignée transgénique pour laquelle nous disposions de peu de données.

Line transect surveys are widely used in Neotropical rainforests to estimate the population abundance of medium- and large-sized vertebrates. The use of indices such as encounter rate has been criticized because the probability of animal detection may fluctuate due to the heterogeneity of environmental conditions among sites. In addition, the morphological and behavioral characteristics (biological traits) of species affect their detectability. In this study, we compared the extent to which environmental conditions and species' biological traits bias abundance estimates in terra firme rainforests in French Guiana. The selected environmental conditions included both physical conditions and forest structure covariates, while the selected biological traits included the morphological and behavioral characteristics of species. We used the distance sampling method to model the detection probability as an explicit function of environmental conditions and biological traits and implemented a model selection process to determine the relative importance of each group of covariates. Biological traits contributed to the variability of animal detectability more than environmental conditions, which had only a marginal effect. Detectability was best for large animals with uniform or disruptive markings that live in groups in the canopy top. Detectability was worst for small, solitary, terrestrial animals with mottled markings. In the terra firme rainforests that represent ~80% of the Amazonia and Guianas regions, our findings support the use of relative indices such as the encounter rate to compare population abundance between sites in species-specific studies. Even though terra firme rainforests may appear similar between regions of Amazonia and the Guianas, comparability must be ensured, especially in forests disturbed by human activity. The detection probability can be used as an indicator of species' vulnerability to hunting and, thus, to the risk of local extinction. Only a few biological trait covariates are required to correctly estimate the detectability of the majority of medium- and large-sized vertebrates. Thus, a biological trait model could be useful in predicting the detection probabilities of rare, uncommon, or localized species for which few data are available to fit the detection function.

BACKGROUND AND PURPOSE: Neonicotinoid insecticides are described as poor agonists of mammalian nicotinic ACh receptors. In this paper, we show that their effects on mammalian nicotinic receptors differ between compounds. EXPERIMENTAL APPROACH: Two‐electrode voltage‐clamp electrophysiology was used to characterize the pharmacology of three neonicotinoid insecticides on nicotinic α7 receptors expressed in Xenopus oocytes. Single and combined application of clothianidin, acetamiprid and thiamethoxam were tested. RESULTS: Two neonicotinoid insecticides, clothianidin and acetamiprid, were partial agonists of mammalian neuronal α7 nicotinic receptors, whereas another neonicotinoid insecticide, thiamethoxam, which is converted to clothianidin in insect and plant tissues, had no effect. Pretreatment with clothianidin and acetamiprid (10 μM) ACh significantly enhanced the subsequent currents evoked by ACh (100 μM ) whereas pretreatment with thiamethoxam (10 μM) reduced ACh‐induced current amplitudes.A combination of the three neonicotinoids decreased the ACh‐evoked currents. CONCLUSIONS AND IMPLICATIONS: The present findings suggest that neonicotinoid insecticides differ markedly in their direct effects on mammalian α7 nicotinic ACh receptors and can also modulate ACh‐induced currents. Furthermore, our data indicate a previously unknown modulation of mammalian α7 nicotinic receptors by a combination of clothianidin, acetamiprid and thiamethoxam. LINKED ARTICLES: This article is part of a themed section on Nicotinic Acetylcholine Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.11/issuetoc

Producción Científica, Signal transduction in sensory neurons of the mammalian vomeronasal organ (VNO) involves the opening of the canonical transient receptor potential channel Trpc2, a Ca2+-permeable cation channel that is activated by diacylglycerol and inhibited by Ca2+-calmodulin. There has been a long-standing debate about the extent to which the second messenger inositol 1,4,5-trisphosphate (InsP3) and type 3 InsP3 receptor (InsP3R3) are involved in the opening of Trpc2 channels and in sensory activation of the VNO. To address this question, we investigated VNO function of mice carrying a knockout mutation in the Itpr3 locus causing a loss of InsP3R3. We established a new method to monitor Ca2+ in the endoplasmic reticulum of vomeronasal sensory neurons (VSNs) by employing the GFP-aequorin protein sensor erGAP2. We also performed simultaneous InsP3 photorelease and Ca2+ monitoring experiments, and analysed Ca2+ dynamics, sensory currents, and action potential or field potential responses in InsP3R3-deficient VSNs. Disruption of Itpr3 abolished or minimized the Ca2+ transients evoked by photoactivated InsP3, but there was virtually no effect on sensory activation of VSNs. Therefore, InsP3R3 is dispensable for primary chemoelectrical transduction in mouse VNO. We conclude that InsP3R3 is not required for gating of Trpc2 in VSNs., Deutsche Forschungsgemeinschaf (grant CH920/2-1), Sonderforschungsbereich 894 (project A17), Transregio - SFB (projects P09 and P10), Ministerio de Economía, Industria y Competitividad (grant BFU2014-53469P)

Astroviruses are known to infect humans and a wide range of animal species, and can cause gastroenteritis in their hosts. Recent studies have reported astroviruses in bats in Europe and in several locations in China. We sampled 1876 bats from 17 genera at 45 sites from 14 and 13 provinces in Cambodia and Lao PDR respectively, and tested them for astroviruses. Our study revealed a high diversity of astroviruses among various Yangochiroptera and Yinpterochiroptera bats. Evidence for varying degrees of host restriction for astroviruses in bats was found. Furthermore, additional Pteropodid hosts were detected. The astroviruses formed distinct phylogenetic clusters within the genus Mamastrovirus, most closely related to other known bat astroviruses. The astrovirus sequences were found to be highly saturated indicating that phylogenetic relationships should be interpreted carefully. An astrovirus clustering in a group with other viruses from diverse hosts, including from ungulates and porcupines, was found in a Rousettus bat. These findings suggest that diverse astroviruses can be found in many species of mammals, including bats., Highlights • Diverse astroviruses detected in bats in Lao PDR and Cambodia • High polymorphism of astroviruses found in insectivorous and frugivorous bats • High level of genome saturation and hypermutation potential evidenced in astrovirus • Detection of additional astrovirus bat hosts, i.e. nectar bats from the genus Eonycteris • Discovery of a new species of astrovirus in fruit bats (Rousettus sp.), Graphical abstract. Image 1

International audience; BACKGROUND:We previously showed that the homeodomain transcription factor HOXB9 is expressed in mammalian oocytes and early embryos. However, a systematic and exhaustive study of the localization of the HOXB9 protein, and HOX proteins in general, during mammalian early embryonic development has so far never been performed.RESULTS:The distribution of HOXB9 proteins in oocytes and the early embryo was characterized by immunofluorescence from the immature oocyte stage to the peri-gastrulation period in both the mouse and the bovine. HOXB9 was detected at all studied stages with a dynamic expression pattern. Its distribution was well conserved between the two species until the blastocyst stage and was mainly nuclear. From that stage on, trophoblastic cells always showed a strong nuclear staining, while the inner cell mass and the derived cell lines showed important dynamic variations both in staining intensity and in intra-cellular localization. Indeed, HOXB9 appeared to be progressively downregulated in epiblast cells and only reappeared after gastrulation had well progressed. The protein was also detected in the primitive endoderm and its derivatives with a distinctive presence in apical vacuoles of mouse visceral endoderm cells.CONCLUSIONS:Together, these results could suggest the existence of unsuspected functions for HOXB9 during early embryonic development in mammals.

The neuropeptide kisspeptin and its receptor, KiSS1R, govern the reproductive timeline of mammals by triggering puberty onset and promoting ovulation by stimulating gonadotrophin-releasing hormone (GnRH) secretion. To overcome the drawback of kisspeptin short half-life we designed kisspeptin analogs combining original modifications, triazole peptidomimetic and albumin binding motif, to reduce proteolytic degradation and to slow down renal clearance, respectively. These analogs showed improved in vitro potency and dramatically enhanced pharmacodynamics. When injected intramuscularly into ewes (15 nmol/ewe) primed with a progestogen, the best analog (compound 6, C6) induced synchronized ovulations in both breeding and non-breeding seasons. Ovulations were fertile as demonstrated by the delivery of lambs at term. C6 was also fully active in both female and male mice but was completely inactive in KiSS1R KO mice. Electrophysiological recordings of GnRH neurons from brain slices of GnRH-GFP mice indicated that C6 exerted a direct excitatory action on GnRH neurons. Finally, in prepubertal female mice daily injections (0.3 nmol/mouse) for five days significantly advanced puberty. C6 ability to trigger ovulation and advance puberty demonstrates that kisspeptin analogs may find application in the management of livestock reproduction and opens new possibilities for the treatment of reproductive disorders in humans.

Spermatozoan quality can be evaluated in different ways, here we focus on the analysis of DNA, RNA and epigenetic status of germ cells. These characterizations also can be the bases for explaining sperm quality at other levels, so we will see how some of these molecules could affect other sperm quality markers. Moreover, we consider the possibility of using some of these molecules as predictors of sperm quality in terms of the ability to produce healthy offspring. The relevant effect of different types of RNA molecules in germ line specification and spermatogenesis and the importance of germ cell DNA integrity and a proper epigenetic pattern will be also discussed. Although most studies at this level have been performed in mammals, some information is available for fish; these recent discoveries in fish models are included. We provide a general overview on how these molecules could have a deep influence in the final sperm quality., SI

National audience

The quiet embryo hypothesis postulates that early embryo viability is associated with a relatively low metabolism (Leese, 2002 BioEssays 24: 845-849). This proposal is re-visited here using retrospective and prospective data on the metabolic activity and kinetics of preimplantation development alongside the concept that an optimal range of such indices and of energetic efficiency influences embryogenesis. It is concluded that these considerations may be rationalized by proposing the existence of a "Goldilocks zone," or as it is known in Sweden, of lagom-meaning "just the right amount"-within which embryos with maximum developmental potential can be categorized. Mol. Reprod. Dev. 83: 748-754, 2016 © 2016 Wiley Periodicals, Inc.

After the publication of this work [1], we noticed there was an error in Fig. 5 where −1,0 and 1 are incorrectly displayed in the y-axis in panel b. Please see the corrected Fig. 5 below. We apologize for this error. Fig. 5 llele-specific RNA-seq on three NPC lines identifies three distal regions of genes that escape XCI. a Ratio of Xi/Xa (y-axis; for each of the three NPC lines sorted from highest to lowest) for genes showing a log2 ratio of at least −5. We set ...

La reproduction recouvre l’ensemble des processus biologiques qui permettent d’assurer la survie d’une espèce grâce à la naissance de nouveaux individus. Cette propriété fondamentale et obligatoire du monde vivant repose sur un mécanisme efficace et extrêmement complexe. Chez les vertébrés, c’est l’axe hypothalamo-hypophyso-gonadique qui est le cadre anatomique responsable de la compétence reproductive et donc de la pérennité des espèces. La coordination de ce système biologique à trois étages repose sur le contrôle neuronal de libération de la « Gonadotrophin Releasing Hormone » (GnRH), système localisé dans la partie rostrale de l’hypothalamus. La libération de GnRH dans le système porte hypothalamo-hypophysaire stimule la sécrétion des gonadotropines hypophysaires qui sont impliquées dans le déclenchement de la puberté et la régulation de la fonction de reproduction. Cette revue fournit des éléments de compréhension sur le fonctionnement du contrôle neuroendocrine de l’axe hypothalamo-hypophyso-gonadique chez les mammifères, en particulier, sur les propriétés du système à GnRH, le contrôle neuroendocrinien des cycles ovariens, l’effet de neuropeptides hypothalamiques «kisspeptin » sur les neurones à GnRH, le déclenchement de la puberté, la saisonnalité et conclue sur les perspectives de recherche dans cette discipline de la neurobiologie., Reproduction covers all biological processes that ensure the survival of species through the birth of new individuals. This fundamental and mandatory property of any organism is based on an efficient and highly complex mechanism. In vertebrates, the hypothalamicpituitary- gonadal axis is the anatomical substrate responsible for the reproductive competence and therefore the sustainability of the species. The coordination of this three-stage-based biological system relies on the neural control of the gonadotrophin releasing hormone (GnRH) release. This system is localized in the rostral part of the ventral hypothalamus. GnRH is released in the hypophyseal portal system and stimulates the secretion of the pituitary gonadotropins that are involved in the onset of puberty and the regulation of reproductive function. This review provides understanding about the mechanisms of the neuroendocrine control of the hypothalamicpituitary- gonadal axis, in particular, on the properties of the system onto the GnRH neuroendocrine control of ovarian cycles, the effect of hypothalamic neuropeptides (kisspeptin) on GnRH neurons, the onset of puberty, and the seasonality of reproduction and concludes on research perspectives in this rejuvenated field of neurobiology.

L’influence du poids et des apports énergétiques sur la fertilité chez les animaux, mais aussi chez l’Homme est reconnue depuis très longtemps. Les animaux ou individus en mauvaise condition, ou perdant du poids, ont généralement des performances reproductives décevantes. Les pertes économiques associées à l’infertilité sont parfois importantes, et dépassent chez le bovin largement le coût de l’insémination et de la semence. De nombreux arguments suggèrent que l’influence de la nutrition sur la reproduction s’exerce par l’intermédiaire des composants du régime alimentaire comme les lipides, le glucose, les acides aminés et les minéraux au niveau de l’axe hypothalamo-hypophysaire et aussi directement au niveau des gonades. Ces effets nutritionnels peuvent aussi s’exercer par une modulation des hormones du métabolisme comme l’insuline, l’insulin-like growth factor 1, l’hormone de croissance, la ghréline, les hormones thyroïdiennes ou encore les hormones produites et secrétées par le tissu adipeux blanc. Dans cette revue nous rapportons les effets connus de ces nutriments et hormones métaboliques sur le développement folliculaire, les cellules ovariennes, la qualité ovocytaire ainsi que sur le développement embryonnaire précoce en prenant l’exemple de différentes espèces de mammifères., The influence of weight and energy intake on fertility animals and humans has been known for a long time. Animals in poor condition, or losing weight, have generally poor reproductive performance. Economic losses associated with infertility can be very important and for example in cattle, they can considerably exceed the cost of artificial insemination. Some evidence suggests that the effects of nutrition on reproductive function are mediated through dietary components such as lipids, glucose, amino acids, and minerals acting on the hypothalamic-pituitary axis but also directly on the gonads. These nutritional effects may also be mediated through changes in metabolic hormones such as insulin, insulin-like growth factor 1, growth hormone, ghrelin, thyroid hormones or hormones produced and secreted by the white adipose tissue. Here, we will review the known effects of these nutritional metabolites, nutrients and metabolic hormones on the follicular development, the activity of ovarian cells, oocyte quality and on early embryonic development in different mammalian species.

International audience

International audience; Astroviruses are emerging RNA viruses that cause enteropathogenic infections in humans and in other mammals. The identification of astroviruses in a wide range of animals highlights the zoonotic importance of these viruses. Bats can harbor many different viruses, among which some are highly pathogenic for humans (for instance, Nipah, Ebola and SARS coronavirus), and also several astroviruses. As some RNA viruses can be directly transmitted from bats to humans, it is crucial to collect data about their frequency, genetic diversity and phylogenetic characterization. In this study, we report the molecular identification of 44 new astroviruses (with a detection rate of 4.5%) in 962 apparently healthy bats that belong to five different species and that were captured in different caves in NorthEast Gabon, Central Africa. Our results show that bat astroviruses form a group that is genetically distinct from astroviruses infecting other mammals. Moreover, these astroviruses showed an important genetic diversity and low host restriction in bat species.

La biochronologie des Carnivores est une réalité. Un exemple, celui de la population des Canis lupus de Romain-la-Roche (Doubs) illustre l’utilisation des Canidés. Le second exemple de la population d’Ursus spelaeus d’Azé 1-3 (Saône-et-Loire) montre tout l’intérêt de la biochronologie des Ursidés. Ces résultats biochronologiques sont discutés à la lumière de tous les éléments de datation obtenus par ailleurs. On peut utiliser certaines populations de Carnivores moyennant un certain nombre de conditions favorables qui doivent être réunies. The biochronology of the Carnivores has reality. The example of the population of Canis lupus of Romain-la-Roche (Doubs) illustrates the contribution of the Canids. The second example, the population of Ursus spelaeus of Azé 1-3 (Saône-et-Loire), demonstrates that the Ursids are of great interest. These biochronological results are discussed in relation to any of dating processes. Some of the populations of Carnivores can be used for dating by biochronology only if some favourable conditions join together.

Cette revue présente l’état des connaissances sur la folliculogenèse et l’ovulation chez les mammifères. La folliculogenèse basale est une phase de croissance folliculaire lente, au cours de laquelle l’ovocyte acquiert la compétence méiotique. La folliculogenèse terminale est une phase de développement rapide, au cours de laquelle le follicule ovulatoire est sélectionné et termine sa maturation, tandis que l’ovocyte acquiert la compétence au développement. La revue décrit les différents changements fonctionnels qui s’opèrent dans le follicule et l’ovocyte au cours de ces deux phases, ainsi que les mécanismes qui les régulent et qui déterminent le quota ovulatoire caractéristique de chaque espèce ou race. Les facteurs-clés identifiés de la folliculogenèse sont les BMP, le KITLG et l’AMH pour le démarrage de croissance folliculaire, l’IGF et l’insuline pour la transition entre folliculogenèse basale et terminale, la FSH pour le début de la folliculogenèse terminale et la sélection des follicules ovulatoires, et la LH pour le développement folliculaire final, la maturation ovocytaire et l’ovulation. L’ovulation est déclenchée par une décharge préovulatoire de LH qui induit la maturation du complexe cumulus-ovocyte dans le follicule ovulatoire, suivie de la rupture de la paroi folliculaire et de la formation du corps jaune. La folliculogenèse ovarienne est contrôlée par des facteurs externes, tels que la photopériode et la nutrition, et c’est essentiellement le système hypothalamo-hypophysaire qui intègre les signaux endocriniens et environnementaux. Des modifications de l’apport alimentaire, relayées par des variations de signaux hormonaux et métaboliques, modulent l’activité de l’axe hypothalamo-hypophyso-ovarien à ses différents étages., This review is a state of the art on follicullogenesis and ovulation in mammals. Basal folliculogenesis is a phase of slow follicular growth, during which the oocyte acquires meiotic competence. Terminal folliculogenesis is a phase of rapid development, during which the ovulatory follicle is selected and completes its maturation while the oocyte acquires developmental competence. This review describes the different functional changes occurring within follicles and oocytes throughout these two phases, the underlying regulatory mechanisms and the mechanisms that determine natural ovulation rate in different species and breeds. Known key factors for folliculogenesis are BNTP, KITLG and AMH for the initiation of follicular growth, IGF and insulin for transition between basal and terminal folliculogenesis, FSH for the outset of terminal folliculogenesis and the selection of ovulatory follicles, and LH for final follicular development, oocyte maturation and ovulation. Ovulation is triggered by a preovulatory LH surge that induces maturation of the cumulus oocyte complex within the ovulatory follicle, rupture of the follicular wall and corpus luteum formation. Ovarian folliculogenesis is controlled by external factors such as photoperiod and nutrition, and the hypothalamo-pituitary system integrates endocrine and environmental signals. Nutritional supply, relayed by hormonal and metabolic signals, can modulate both the hypothalamo-pituitary and ovarian activity.

So far, research on trypanosomatid infections has been driven by 'disease by disease' approaches, leading to different concepts and control strategies. It is, however, increasingly clear that they share common features such as the ability to generate long-lasting asymptomatic infections in their mammalian hosts. Trypanotolerance, long integrated in animal African trypanosomiasis control, historically refers to the ability of cattle breeds to limit Trypanosoma infection and pathology, but has only recently been recognized in humans. Whilst trypanotolerance is absent from the vocabulary on leishmaniasis and Chagas disease, asymptomatic infections also occur. We review the concept of trypanotolerance across the trypanosomatids and discuss the importance of asymptomatic carriage in the current context of elimination.

Afin de délimiter l'un des lieux du dialogue entre les archéologues et les ethnologues, afin d'en estimer ensuite la portée et les limites, l'auteur, ethnologue, livre au cours de cet essai le type de réponses que sa discipline peut fournir au problème de l'interprétation des figures que nous propose l'art rupestre sud-américain sans ignorer les difficultés épistémologiques engendrées par une telle entreprise. Elle a retenu la figure omniprésente du cervidé dans l'art pariétal des basses terres de l'Amérique du Sud et s'est proposée de dégager les thèmes sous - jacents aux histoires de cerf, de biche et de daguet que content les littératures orales des sociétés amazoniennes. Au fur et à mesure de son développement, cette recherche révélait la nécessité d'un recours à d'autres disciplines: la paléontologie, essentielle à l'archéologie, est limitée ici à une ébauche de la colonisation du continent sud-américain par des immigrés nordiques dont les cervidés et cette ébauche sera soumise à la retaille des spécialistes; en même temps nous ressentions tous les besoins d'une étude zoologique et ethno-zoologique pour préciser les habitants, les formes corporelles, les couleurs et les comportements des cervidés à partir desquels les hommes vont moduler les relations qu'ils entretiennent avec ces animaux. Cette étude menée à bien, l'auteur peut amorcer la recherche proprement ethnologique et s'appuie dès lors sur les pratiques, la science et la littérature orale des sociétés amazoniennes contemporaines ou historiques pour décrire le pôle zoo - ethnologique de la relation des hommes aux cervidés. Pour respecter les limites assignées à cette tentative, des zones d'ombre ont dû être conservées et des analyses raccourcies, néanmoins ce rapide parcours permet de suivre l'homme dans ses fonctions de prédateur et de consommateur, de le voir investir cette relation de liens idéologiques. A travers les constructions successives de l'image des cervidés pour les cultures amazoniennes, l'auteur esquisse enfin la position sémantique du terme "cervidé" dans la pensée mythique et sa signification pour l'imaginaire amazonien. C'est cette symbolique du cervidé qui interroge les archéologues. Le lieu du dialogue ne serait-il pas donné par ces archétypes qu'élaborent les structures imaginaires et qui sous-tendent les réalisations singulières et historiques propres à chaque culture?. Illustration de la couverture: Os gravés et sculptés matsiguenga. Sur l'os du haut sont représentés des traces de daguet rouge, sur celui du bas, les dessins dorsaux d'une carapace de tortue. Les deux os se suivent dans la frange qui orne un bandeau de portage fait sur le rio Picha. Con el fin de deslindar uno de los campos del diálogo entre los arqueólogos y los etnólogos y de estimar luego el alcance de dicho diálogo y sus límites, la autora, etnóloga, aporta en este ensayo el tipo de respuestas que su disciplina puede proporcionar al problema de la interpretación de las figuras que muestra el arte rupestre sudamericano, eso sin ignorar las dificultades epistemológicas engendradas por esta acción. Al escoger la figura omnipresente del cérvido en el arte parietal de las tierras bajas de América del Sur, se ha propuesto aclarar los temas subyacentes a las historias de ciervo, de cierva y de cervato que relatan las literaturas orales de las sociedades amazónicas. A medida de su desarrollo, esta investigación reveló la necesidad de recurrir a otras disciplinas como ser la paleontología, la zoología y la etnozoología. La paleontología, esencial en arqueología, se limita aquí a un esbozo de la colonización del continente sudamericano por inmigrantes nórdicos, entre los cuales se encuentran los cérvidos, y este bosquejo será sometido a la opinión de los especialistas para que lo adecúen. Al mismo tiempo todos sentíamos la necesidad de un estudio zoológico y etno-zoológico para precisar los habitats, las formas corporales, los colores y los comportamientos de los cérvidos, características a partir de las cuales los nombres van a modular las relaciones que mantienen con estos animales. Una vez acabado este estudio, la autora pudo comenzar la investigación propiamente etnológica apoyándose desde entonces sobre las prácticas, la ciencia y la literatura oral de las sociedades amazónicas contemporáneas o históricas para describir el polo zoo-etnológico de la relación entre los hombres y los cérvidos. Para respetar los límites asignados a esta tentativa, se han conservado puntos oscuros y los análisis son breves; no obstante, este rápido recorrido permite seguir al hombre en sus funciones de predador y de consumidor, ver cómo reviste esta relación con lazos ideológicos. A través de las sucesivas construcciones de la imagen de los cérvidos en las culturas amazónicas, el autor esboza por fin la posición semántica del término "cérvido" en el pensamiento mítico y su significado para el imaginario amazónico. Es esta simbólica del cérvido la que plantea un interrogante a los arqueólogos. ¿No se ubicaría el campo del diálogo al nivel de estos arquetipos que elaboran las estructuras imaginarias y que sostienen las realizaciones singulares e históricas propias a cada cultura?. Ilustración de la carátula: Huesos grabados y esculpidos matsiguenga. Sobre el hueso superior están representados rasgos de cervatillo rojo; en el inferior los dibujos dorsales de una caparazón de tortuga. Los dos huesos se encuentran juntos en la franja que adorna una "faja de cargar" hecha en el rio Picha.

Background During early embryonic development, one of the two X chromosomes in mammalian female cells is inactivated to compensate for a potential imbalance in transcript levels with male cells, which contain a single X chromosome. Here, we use mouse female embryonic stem cells (ESCs) with non-random X chromosome inactivation (XCI) and polymorphic X chromosomes to study the dynamics of gene silencing over the inactive X chromosome by high-resolution allele-specific RNA-seq. Results Induction of XCI by differentiation of female ESCs shows that genes proximal to the X-inactivation center are silenced earlier than distal genes, while lowly expressed genes show faster XCI dynamics than highly expressed genes. The active X chromosome shows a minor but significant increase in gene activity during differentiation, resulting in complete dosage compensation in differentiated cell types. Genes escaping XCI show little or no silencing during early propagation of XCI. Allele-specific RNA-seq of neural progenitor cells generated from the female ESCs identifies three regions distal to the X-inactivation center that escape XCI. These regions, which stably escape during propagation and maintenance of XCI, coincide with topologically associating domains (TADs) as present in the female ESCs. Also, the previously characterized gene clusters escaping XCI in human fibroblasts correlate with TADs. Conclusions The gene silencing observed during XCI provides further insight in the establishment of the repressive complex formed by the inactive X chromosome. The association of escape regions with TADs, in mouse and human, suggests that TADs are the primary targets during propagation of XCI over the X chromosome. Electronic supplementary material The online version of this article (doi:10.1186/s13059-015-0698-x) contains supplementary material, which is available to authorized users.

Graphical Abstract Asymmetry in host and multi-parasite interactions as a framework for investing the likely determinants of parasite species richness and its ecological and evolutionary impacts on host, Highlights • This review summarized the factors explaining parasite diversity among host species. • Ecological and epidemiological theories help to find these potential factors. • Life-history theory helps to test effects of parasite richness on hosts. • This review is illustrated with comparative studies on parasites of mammals., The present review summarized the factors or determinants that may explain parasite diversity among host species and the consequences of this parasite diversity on the evolution of host-life history traits. As host–parasite interactions are asymmetrical exploited–exploiter relationships, ecological and epidemiological theories produce hypotheses to find the potential determinants of parasite species richness, while life-history theory helps for testing potential consequences on parasite diversity on the evolution of hosts. This review referred only to studies that have specifically controlled or took into account phylogenetic information illustrated with parasites of mammals. Several points needing more investigation were identified with a special emphasis to develop the metabolic theory of epidemiology.

In mammals, oocytes develop inside the ovarian follicles, this process is strongly supported by the surrounding follicular environment consisting of cumulus, granulosa and theca cells, and follicular fluid. In the antral follicle, the final stages of oogenesis require large amounts of energy that is produced by follicular cells from substrates including glucose, amino acids and fatty acids (FAs). Since lipid metabolism plays an important role in acquiring oocyte developmental competence, the aim of this study was to investigate site-specificity of lipid metabolism in ovaries by comparing lipid profiles and expression of FA metabolism-related genes in different ovarian compartments. Using MALDI Mass Spectrometry Imaging, images of porcine ovary sections were reconstructed from lipid ion signals for the first time. Cluster analysis of ion spectra revealed differences in spatial distribution of lipid species among ovarian compartments, notably between the follicles and interstitial tissue. Inside the follicles analysis differentiated follicular fluid, granulosa, theca and the oocyte-cumulus complex. Moreover, by transcript quantification using real time PCR, we showed that expression of five key genes in FA metabolism significantly varied between somatic follicular cells (theca, granulosa and cumulus) and the oocyte. In conclusion, lipid metabolism differs between ovarian and follicular compartments.

International audience; We investigated the role of environmental filtering as an underlying mechanism of assembly of compound communities of fleas parasitic on Palearctic small mammals at two spatial scales; a continental scale (encompassing regions across the entire Palearctic) and a regional scale (across sampling localities within Slovakia). We used the three‐table ordination (the RLQ analysis) and its extended version that links species occurrences with geographic space, environmental variables, and species traits and phylogeny (the ESLTP analysis). We asked whether environmental filtering acts as an assembly rule of compound communities of fleas and, if yes, a) whether the effect of environment on species composition of compound communities of fleas differs between spatial scales and b) what are the relative importance of the abiotic and host environments. We found that compound communities of fleas are, to a great extent, assembled via environmental filters that represent interplay between filtering via abiotic environment and filtering via host composition. The relative importance of these two components of environmental filtering differed between spatial scales. Host composition had a stronger effect on flea assembly than abiotic environment on the continental scale, while the opposite was true for the regional scale. The likely reason behind this scale‐dependence is that communities on the regional scale are mainly governed by ecological and epidemiological processes, while communities on the continental scale are mainly affected by evolutionary, biogeographic and historical forces.

Les qualités des carcasses et des viandes/chairs des espèces d’intérêt agronomique (mammifères, espèces aviaires et poissons) dépendent en grande partie des caractéristiques et des proportions relatives des différents compartiments tissulaires, principalement les fibres et le tissu conjonctif musculaires et les tissus adipeux. Dans cette revue, nous décrivons la mise en place de ces trois compartiments au cours du développement embryonnaire et foetal, ainsi que leur croissance après la naissance ou l’éclosion. Les fibres musculaires et le tissu conjonctif des muscles du tronc sont issus de domaines embryonnaires distincts de ceux à l’origine des muscles des membres et de la tête. L’origine embryonnaire des adipocytes blancs reste à établir, mais est vraisemblablement multiple et dépendante de la localisation anatomique des tissus adipeux. La croissance post-embryonnaire des muscles et des tissus adipeux implique la prolifération puis la différenciation de cellules progénitrices non-embryonnaires. Le nombre total de fibres musculaires est fixé aux deux tiers ou aux quatre cinquièmes de la gestation chez le bovin et le porc respectivement, et dès la naissance chez les volailles alors qu’il augmente encore après l’éclosion chez certains poissons. Le nombre d’adipocytes augmente durant la croissance foetale et dans une moindre mesure après la naissance. Des interactions entre tissus au cours de la croissance, auparavant suggérées, sont maintenant démontrées par l’identification de protéines sécrétées par les cellules musculaires et adipeuses qui participent au dialogue entre tissus., The qualities of carcasses and products of agronomic species depend largely on characteristics and relative proportions of the different tissue components, mainly muscle fibers, muscular connective tissue and adipose tissues. This review is devoted to the prenatal and neonatal development of these three components. The embryonic origin of myofibers and connective tissue from trunk muscle differs from that of limb and head muscles. The embryonic origin of white adipocytes remains to be established and may depend on the anatomical location of adipose tissues. The post-embryonic growth of muscles and adipose tissues involves the proliferation and then the differentiation of fetal or adult progenitors. The total number of muscle fibers is fixed at around 66% (bovine) or 80% (pig) of gestation or at birth in poultry, while it increases after hatching in some fishes. The number of adipocytes increases predominantly during fetal growth and to a lesser extent after birth. Interactions between tissues during growth, formerly suggested, have now been demonstrated by the identification of proteins secreted by muscle and adipose cells that participate in the cross-talk between tissues.

Article suite au congrès :31st Meeting of the European-Embryo-Transfer-Association (AETE). 11-12 September 2015, Ghent, Belgique; After a long journey travelling up the maternal tract the spermatozoa will meet the oocyte. As a result, an early embryo will promptly commence its development while travelling down the oviduct. These short but vital journeys of gametes and embryos are accompanied by important changes in the maternal tract. In particular, from the oviduct, which provides an optimal environment for gamete maturation and transport, fertilization and early embryo development. In fact, to achieve a successful pregnancy the oviduct should keep a fruitful dialogue with the gametes followed by an appropriate communication with the embryo(s). In the present review, the transcriptomic and proteomic changes induced by gametes and embryos in the oviduct as a result of this early dialogue will be reported. A special mention of the differential conversation between the oviduct and X and Y-chromosome-bearing spermatozoa, which might be at the basis of gender selection, will be provided. Subsequently, the ability of the embryo to modulate its own oviductal environment thus avoiding its maternal rejection will be discussed. Ultimately, a third player will be introduced in this dialogue, exosomes/microvesicles, which have been proposed as early mediators of these maternal-gamete/embryo interactions. Snooping on the private conversation between the oviduct and gametes/embryo may provide some molecular clues about the mechanisms that mediate these interactions. Moreover, knowing the genes and proteins that pilot the success of the early reproductive events will offer great opportunities for the improvement of assisted reproductive technologies and animal breeding efficiency.