DISSERTATION RESEARCH: Stress-induced Parental Effects on Offspring Mate Choice: Ultimate Drivers and Proximate Mechanisms using the Threespine Stickleback (Gasterosteus aculeatus)

University Of Denver, Denver CO

Investigators

Abstract

The influence of parents on their offspring depends on the parents' own experiences. Often, these parental effects prepare offspring for the parental environment. For instance, parents exposed to predators can produce offspring that are better able to survive the same predators. Offspring reproduction may also be influenced by parental experiences, but this remains an untested and important question. Parental effects are one way that organisms can respond quickly to rapid environmental change. Yet, parental effects could be bad for offspring if parent and offspring environments do not match. This project tests whether stress experienced by parents influences the mate choices made by their offspring much later, measures the costs and benefits of these effects in a changing environment, and identifies the underlying genomic mechanisms. This project will also lead to the publication of a new, active-learning case study based on this research, and use it to bring modern evolutionary research to middle school classrooms. The proposed work capitalizes on an emerging model system, threespine sticklebacks (Gasterosteus aculeatus), in which both parents make substantial, distinct contributions to offspring development and females have quantifiable preferences for male traits. This proposal will reveal the relative importance of maternal, paternal, and parental experience on offspring reproductive phenotypes (Aim 1), whether transgenerational plasticity is adaptive or maladaptive when parental and offspring environments do or do not match (Aim 2), and if epigenetic states underlie changes in offspring mate choice behavior (Aim 3). No parents, mothers, fathers, or both parents will be exposed to predation and the mating decisions of their offspring tested under conditions in which parent and offspring environments do or do not match. Preliminary analyses show that paternal predator-exposure tends to shift daughters' mate preferences, while maternal predator-exposure alters daughters' interest in mating. If parental effects modify mate choice, they may facilitate rapid responses to environmental change, but whether these effects are adaptive depends on agreement between parent and offspring environments. Finally, parental effects on mate choice may be underlain by genome-wide variation in epigenetic states, specifically DNA methylation. Aim 3 uses new techniques to compare genome-wide methylation patterns of offspring from families in which no parents, mothers, fathers, or both parents were exposed to predation. This proposal will establish the role of parental effects on reproductive phenotypes for individual fitness and population dynamics in anthropogenically altered environments.