Meeting Abstract
Nonapeptides play a crucial role in mediating reproduction, aggression, and parental care across taxa. In fishes, arginine vasotocin (AVT) expression is related to social and/or reproductive status in most male fishes studied to date, and is linked to territorial defense, paternal care, and courtship. Despite the plethora of studies in male fishes, it remains unknown if AVT in females varies with reproductive state and is similarly implicated in reproductive and maternal care behaviors. Using the mouthbrooding African cichlid fish Astatotilapia burtoni, we compared the number and size of AVT cells in the preoptic area of females of different reproductive states. Gravid and mouthbrooding females had similar numbers of parvocellular, magnocellular, and gigantocellular cells. Parvocellular cells were of similar size in gravid and brooding females, but gravid females had larger magnocellular and gigantocellular cells compared to mouthbrooding females. In addition, the size of gigantocellular cells within brooding females correlated with the number of days brooding, such that late-stage brooding females had larger AVT cells than mid-stage brooding females, suggesting a role in maternal care. To investigate this further, brains from females displaying maternal care behaviors (fry protection) will be stained for AVT and the neural activation marker, egr1. Together, these data indicate that AVT neurons change across the reproductive cycle in females, similar to that seen in males. These data on females complement studies in male A. burtoni, providing a comprehensive picture of the regulation and potential function of different AVT cell types in reproduction and social behaviors in both sexes.
