Meslin C.,CNRS Physiology of Reproduction and Behaviors |
Meslin C.,French National Center for Scientific Research |
Meslin C.,University of Tours |
Meslin C.,Institute Franc Ais Du Cheval Et Of Lequitation |
And 24 more authors.
Genome Biology and Evolution | Year: 2015
Free fatty acid receptors (FFAR) belong to a family of five G-protein coupled receptors that are involved in the regulation of lipid metabolism, so that their loss of function increases the risk of obesity. The aim of this study was to determine the expansion of genes encoding paralogs of FFAR2 in the chicken, considered as amodel organism for developmental biology and biomedical research. By estimating the gene copy number using quantitative polymerase chain reaction, genomic DNA resequencing, and RNA sequencing data, we showed the existence of 23 ±1.5 genes encoding FFAR2 paralogs in the chicken genome. The FFAR2 paralogs shared an identity from 87.2%up to 99%. Extensive gene conversion was responsible for this high degree of sequence similarities between these genes, and this concerned especially the four amino acids known to be critical for ligand binding. Moreover, elevated nonsynonymous/synonymous substitutionratios onsomeamino acids withinor inclose-vicinity of the ligand-bindinggroove suggest that positive selectionmay have reduced the effective rate of gene conversion in this region, thus contributing to diversify the function of some FFAR2 paralogs. All the FFAR2 paralogs were located on a microchromosome in a same linkage group. FFAR2 genes were expressed in different tissues and cells such as spleen, peripheral blood mononuclear cells, abdominal adipose tissue, intestine, and lung, with the highest rate of expression in testis. Further investigations are needed to determine whether these chicken-specific events along evolution are the consequence of domestication and may play a role in regulating lipid metabolism in this species. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
Coulon M.,French National Institute for Agricultural Research |
Coulon M.,VetAgro Sup |
Levy F.,CNRS Physiology of Reproduction and Behaviors |
Levy F.,French National Center for Scientific Research |
And 10 more authors.
Stress | Year: 2014
Consequences of prenatal stress on mother-young relationships are well-documented in altricial mammals but less so in precocial mammals. In this study, we investigated the effects of unpredictable aversive events on maternal behavior and mutual mother-young recognition in pregnant ewes while accounting for modulatory effects of ewe reactivity. From a population of 120 Romane-breed ewes, we selected 20 high-responsive (HR) and 20 low-responsive (LR) ewes according to pre-mating reactivity assessed in isolation tests. Over the final third of pregnancy, 10 HR ewes and 10 LR ewes were exposed daily to various aversive events such as social isolation, mixing and transport (stressed ewes), while the other 20 ewes were not exposed to aversive events (control ewes). Although the treatment induced chronic stress, physiologically confirmed by an increase in salivary cortisol following transport and sham shearing, maternal behavior of stressed ewes observed during the first 30 min postpartum and in the selectivity test 1 h 30 min later did not differ from controls. However, in a maternal motivation test performed 48 h postpartum, stressed ewes vocalized less than controls when separated from their lambs, and walked less readily past an unknown object to reach their lambs. Lambs of stressed ewes spent more time near their dam in a preference test performed 15 h after birth compared to control-ewe lambs. HR ewes spent more time grooming their lambs than LR ewes. We posit that domestication could have selected animals displaying robust expression of maternal behavior related to social reactivity and producing offspring that are better adapted to challenging situations. © 2014 Informa UK Ltd.