Search

Characterizing animal dispersal patterns and the rational behind individuals’ transfer choices is a long‐standing question of interest in evolutionary biology. In wild western gorillas (Gorilla gorilla), a one‐male polygynous species, previous genetic findings suggested that, when dispersing, females might favor groups with female kin to promote cooperation, resulting in higher‐than‐expected within‐group female relatedness. The extent of male dispersal remains unclear with studies showing conflicting results. To investigate male and female dispersal patterns and extragroup paternity, we analyzed long‐term field observations, including female spatial proximity data, together with genetic data (10 autosomal microsatellites) on individuals from a unique set of four habituated western gorilla groups, and four additional extragroup males (49 individuals in total). The majority of offspring (25 of 27) were sired by the group male. For two offspring, evidence for extragroup paternity was found. Contrarily to previous findings, adult females were not significantly more related within groups than across groups. Consistently, adult female relatedness within groups did not correlate with their spatial proximity inferred from behavioral data. Adult females were similarly related to adult males from their group than from other groups. Using R ST statistics, we found significant genetic structure and a pattern of isolation by distance, indicating limited dispersal in this species. Comparing relatedness among females and among males revealed that males disperse farer than females, as expected in a polygamous species. Our study on habituated western gorillas shed light on the dispersal dynamics and reproductive behavior of this polygynous species and challenge some of the previous results based on unhabituated groups., We found evidence for extra‐group paternity for two offspring. Adult females were not significantly more related within groups than between groups and were similarly related to adult males from their group than from other groups. Comparing relatedness among females and among males revealed that males disperse farer than females.

Most mirror-image stimulation studies (MIS) have been conducted on social and diurnal animals in order to explore self-recognition, social responses, and personality traits. Small, nocturnal mammals are difficult to study in the wild and are under-represented in experimental behavioral studies. In this pilot study, we explored the behavioral reaction of a small nocturnal solitary forager—the grey mouse lemur (Microcebus murinus)—an emergent animal model in captivity. We assessed whether MIS can be used to detect a repeatable behavioral reaction, whether individuals will present a similar reaction toward a conspecific and the mirror, and whether males and females respond similarly. We tested 12 individuals (six males and six females) twice in three different contexts: with a mirror, with a live conspecific, and with a white board as a neutral control. We detected significant repeatability for the activity component of the behavioral reaction. There was a significant effect of the context and the interaction between presentation context and sex for avoidance during the first session for males but not for females. Males avoided the mirror more than they avoided a live conspecific. This pilot study opens a discussion on the behavioral differences between males and females regarding social interactions and reproduction in the nocturnal solitary species, and suggests that males are more sensitive to context of stimulation than females.

We report the genome sequence of Thermococcus sp. EXT12c isolated from a deep-sea hydrothermal vent at the East Pacific Rise 9°N. Microbes in the genus Thermococcus are able to grow anaerobically at high temperature, around neutral pH, and some of them under high hydrostatic pressure.

White adipose tissue (WAT) in humans plays a central role in the physiopathology of obesity with altered metabolic and endocrine functions. The secretions of the adipokines, except adiponectin, are increased and particularly those of the inflammatory and angiogenic adipokines as the granulocyte colony stimulating factor (G-CSF). There is currently few data about the role of G-CSF in human WAT biology. By a transcriptomic approach, our team has shown that G-CSF was the most over-expressed gene in the inflammatory preadipocytes. First, I have characterized G-CSF secretion and expression in human WAT (by real-time PCR and ELISA tests), and I suggested a potential role in the mobilization of endothelialprogenitor cells (ECPs) involved in neoangiogenesis. G-CSF and its receptor are mainly expressed by macrophages isolated from WAT of obese patients. Moreover, G-CSF is more secreted by visceral than subcutaneous WAT of obese patients. In addition, inflammatory macrophages secrete abundantly G-CSF. Preliminary results show that although G-CSF does not seem to have a direct effect on the proliferation of ECPs, the secretory media of obese visceral WAT show a proliferative and attractive effect on ECPs. Thus, G-CSF can be considered a new adipokine, and may participate, by the mobilization of ECPs, in the vascular repair of WAT during human obesity.; Le tissu adipeux blanc humain joue un rôle central dans la physiopathologie de l’obésité. Il subit des altérations de son métabolisme et de sa fonction endocrine. À l’exception de l’adiponectine, les sécrétions des adipokines sont augmentées et, notamment, celles à caractères inflammatoires et angiogéniques. Parmi ces nombreux médiateurs inflammatoires figure le facteur de croissance granulocytaire (G-CSF) dont le rôle dans le tissu adipeux blanc hypertrophique reste encore à préciser. Des travaux de notre équipe ont montré, par une approche transcriptomique, que G-CSF était le gène le plus surexprimé par les pré-adipocytes inflammatoires. Après l’avoir caractérisé au sein du tissu adipeux blanc humain (PCR en temps réel, dosages ELISA), je proposerai un rôle potentiel de G-CSF comme médiateur de la mobilisation des progéniteurs des cellules endothéliales (PCEs) eux-mêmes impliqués dans la néoangiogenèse. G-CSF et son récepteur sont principalement exprimés par les macrophages isolés du tissu adipeux de patients obèses. Au niveau tissulaire, G-CSF est plus sécrété par le tissu adipeux viscéral que par le tissu sous cutané chez les patientes obèses. De plus, les macrophages inflammatoires sécrètent du G-CSF. Des résultats préliminaires montrent que, même si G-CSF ne semble pas avoir d’effet direct sur la prolifération des PCEs, le milieu de sécrétion du tissu adipeux viscéral de patients obèses montre un effet prolifératif et attractant sur ces PCEs. G-CSF peut donc être considéré comme une nouvelle adipokine et pourrait participer, par la mobilisation des PCEs, à la réparation vasculaire du tissu adipeux blanc humain au cours de l’obésité.