paternal effects on offspring development

Paternal Effects on Offspring Behavior

Male stickleback fish Gasterosteus aculeatus build nests out of sand, vegetation, and a glue they produce in their kidneys. They provide all the parental care for the eggs and young fry, including aeration, removing fungus, and protection from predators. As a postdoctoral research associate in Alison Bell's lab at the University of Illinois - Urbana-Champaign, I worked on projects trying to understand more about paternal effects on offspring behavior.

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Offspring are often influenced by the care they receive from their parents, and this is true in stickleback fish as well. However, we know little about the underlying neurogenomic mechanisms. Using a half-sib design, threespine stickleback fish were either raised by their fathers or hand-reared (“orphaned”). Once offspring became juveniles, they were tested in one of three behavioural assays: an open field assay with a simulated predator attack, a social behaviour assay with a simulated predator attack, and a scototaxis assay. Across all three assays, offspring that received parental care exhibited bolder behaviour. Fish in the open field assay had their brains sampled one hour following the simulated attack; brains were sampled at the same time from full-sib controls. These brains were processed for gene expression (via TagSeq) and chromatin accessibility (via ATACseq). Experiencing paternal care affected brain gene expression, but sex and interactions between sex and paternal care were also major factors, despite the fish being reproductively immature. The predator attack had less of an effect on gene expression. Sex, but not paternal care, influenced chromatin accessibility at individual sites, but a network approach suggested important interactions between sex and paternal care in determining chromatin accessibility. Our findings further our understanding of the mechanistic basis for how offspring respond to variation in the care they receive from their parents. 

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We also know that the experiences of both mothers and fathers can influence phenotypes of future generations (transgenerational plasticity). In a collaboration with Jennifer Hellmann, we exposed male fish to a fake predator. When WE raised their babies, their sons grew up and adjusted their parenting behavior AS IF THEY had experienced the predator. The same was true of GRANDSONS if BOTH their grandfathers were exposed! 🤯