Project description:Mammalian infants depend on parental care for survival, with numerous consequences for their behavioral development. We investigated the epigenetic and neurodevelopmental mechanisms mediating the impact of early parental care on social behavior development in prairie voles. We find widespread male specific differential expression of genes related to synaptic transmission and autism in the nucleus accumbens.
Project description:For many species, parental care critically affects offspring survival. But what drives animals to display parental behaviours towards young? In mammals, pregnancy‐induced physiological transformations seem key in preparing the neural circuits that lead towards attraction (and reduced‐aggression) to young. Beyond mammalian maternal behaviour, knowledge of the neural mechanisms that underlie young‐directed parental care is severely lacking. We took advantage of a domesticated bird species, the Japanese quail, for which parental behaviour towards chicks can be induced in virgin non‐ reproductive adults through a sensitization procedure, a process that is not effective in all animals. We used the variation in parental responses to study neural transcriptomic changes associated with the sensitization procedure itself and with the outcome of the procedure (i.e., presence of parental behaviours). We found differences in gene expression in the hypothalamus and bed nucleus of the stria terminalis, but not the nucleus taeniae. Two genes identified are of particular interest. One is neurotensin, previously only demonstrated to be causally associated with maternal care in mammals. The other one is urocortin 3, causally demonstrated to affect young‐directed neglect and aggression in mammals. Because our studies were conducted in animals that were reproductively quiescent, our results reflect core neural changes that may be associated with avian young‐directed care independently of extensive hormonal stimulation. Our work opens new avenues of research into understanding the neural basis of parental care in non‐placental species.
Project description:The discus fish, Symphysodon spp., a South American cichlid, has a unique parental care behavior where fry bite on parental skin mucus after hatching. In this study, we used LC-MS/MS technique to compare the skin mucus proteome composition of male or female discus fish during parental and non-parental care periods. By multivariate statistical analysis, we found clear separations between different periods and between different sexes of mucus proteome. Compared with non-parental female fish, parental female fish had 283 up-regulated and 235 down-regulated expressed proteins. Compared with non-parental male fish, parental male fish had 169 up-regulated and 120 down-regulated expressed proteins. The differentially expressed proteins for male fish were enriched in sulfur relay system, mucin type O-glycan biosynthesis and antigen processing and presentation pathways, while those for female fish were enriched in sulfur relay system, steroid biosynthesis and complement and coagulation cascades pathways. During the parental care, both male and female discus showed an enhanced lipid metabolism, producing more phospholipids and cholesterol. The difference is that male discus had increased tricarboxylic acid cycle producing more energy during the parental care, while females produced more nucleotides especially guanylic acid. Our study could provide new insights into the understanding of the unique mucus supply behavior of discus fish based on proteomic change.
Project description:Motherhood is characterized by dramatic changes in brain and behavior, but less is known about fatherhood. Here we report that male sticklebacks – a small fish in which fathers provide care – experience dramatic changes in neurogenomic state as they become fathers. Some genes are unique to different stages of paternal care, some genes are shared across stages, and some genes are added to the previously acquired neurogenomic state. Comparative genomic analysis suggests that some of these neurogenomic dynamics resemble changes associated with pregnancy and reproduction in mammalian mothers. Moreover, gene regulatory analysis identified transcription factors that are regulated in opposite directions in response to a territorial challenge versus during paternal care. Altogether these results show that some of the molecular mechanisms of parental care might be deeply conserved and might not be sex-specific, and suggest that tradeoffs between opposing social behaviors are managed at the gene regulatory level.
Project description:In socially monogamous prairie voles (Microtus ochrogaster), parental behaviors not only occur in mothers and fathers, but also can exist in virgin males. However, some virgin males display aggressive behaviors towards conspecific pups. Although this behavioral dichotomy in response to pup exposure has been well documented in male virgin voles, little is known about the gene expression changes underlie the parental behavioral differences and their regulatory mechanisms. To address this, we profiled the transcriptome and DNA methylome of hippocampal dentate gyrus of four prairie vole groups, attacker virgin males, parental virgin males, fathers, and mothers. We found a concordant pattern of gene transcription in parental virgin males and fathers, when comparing to the attacker group. The methylome analysis also revealed pathways with genes enriched for epigenetic changes involving both receptor-mediated and secondary messenger signaling across both behavioral phenotypes and sexual experiences. Furthermore, we found correlations between gene expression changes and DNA methylation differences between attacker and parental virgin males, which suggests a canonical gene expression regulatory role of DNA methylation in paternal care. Therefore, our study presents an integrated view of transcriptome and epigenome that provides a DNA epigenetic based molecular insight of paternal behavior.