Genetic variation in the social environment affects behavioral phenotypes of oxytocin receptor mutants in zebrafish

Oxytocin-like peptides have been implicated in the regulation of a wide range of social behaviors across taxa. On the other hand, the social environment, which is composed of conspecifics genotypes, is also known to influence the development of social behavior, creating the possibility for indirect genetic effects. Here we used a knockout line for the oxytocin receptor in zebrafish to investigate how the genotypic composition of the social environment (Es) interacts with the oxytocin genotype (G) of the focal individual in the regulation of its social behavior. For this purpose, we have raised wild-type or knock-out zebrafish in either wild-type or knock-out shoals and tested different components of social behavior in adults. GxEs effects were detected in some behaviors, highlighting the need to control for GxEs effects when interpreting results of experiments using genetically modified animals, since the social environment can either rescue or promote phenotypes associated with specific genes.