Sex-specific transgenerational plasticity in threespined sticklebacks

Introductory paragraph Sex-specific selection pressures can generate different phenotypic optima for males and females in response to the current environment. Less widely appreciated is the possibility of sex-specific transgenerational plasticity (TGP): mothers and fathers may exert different effects on offspring traits and parental cues may persist selectively across generations via only daughters or sons. Here, we demonstrate that maternal and paternal exposure to predation risk has largely distinct effects on offspring behavior in threespined sticklebacks (Gasterosteus aculeatus), with non-additive interactions between maternal and paternal effects on offspring survival and brain gene expression profiles. Further, parental effects on offspring behavior and brain gene expression profiles varied between male and female offspring, suggesting that mothers and fathers activate different developmental programs in sons versus daughters. Altogether these results demonstrate that sex- both of the parent and offspring- influences TGP patterns in ways that may reflect the distinct life history trajectories of males and females.