RNAi and chromatin remodeling pathways regulate reproductive phenotypic plasticity in C. elegans

Environmental cues experienced early in development play a critical role in modulating adult phenotypes through largely uncharacterized mechanisms. We use C. elegans as a model system to investigate the mechanisms by which early life stress regulates adult behavior and physiology. We have shown previously that wildtype adults that briefly passed through an alternate stress‐induced dauer stage (postdauers) exhibit changes in gene expression, genome‐wide chromatin state, small RNA populations, and life‐history traits compared to adults that bypassed the dauer stage (controls). One consequence of early environmental stress is that postdauer adults have a significantly larger brood size than their control adult counterparts, which is dependent on functional chromatin remodeling and small interfering RNA pathways. Reproduction in C. elegans hermaphrodites is sperm‐limited; thus, an increased brood size suggests an increase in sperm production in postdauer development. To test this hypothesis, we are currently conducting a developmental time course in postdauer and control animals to investigate differences in spermatogenesis using DAPI staining and an antibody against major sperm proteins . We will characterize the role of RNAi and chromatin remodeling mechanisms in regulating sperm production by examining for spermatogenesis differences identified in wildtype animals in control and postdauer adults carrying mutations in these pathways, and by performing tissue‐specific rescue experiments. These results will further characterize the role of RNAi and chromatin remodeling as mechanisms regulating changes in gene expression due to environmental stressors early in development that result in adult phenotypic plasticity. Funding: Syracuse University