Meeting Abstract

69-5   11:30 - 11:45  Differential oocyte mRNA provisioning may underlie complex developmental differences in a marine annelid Harry, ND*; Zakas, C; North Carolina State University; North Carolina State University ndharry@ncsu.edu

Early development is controlled by maternal factors, which govern embryogenesis prior to the zygotic genome’s activation. Females package these lipid, protein, and RNA factors into oocytes during oogenesis as part of maternal provisioning. The extent to which maternally provisioned RNAs affect later offspring phenotypic and life-history traits is unknown. However, variation in maternal RNA provisioning may provide selectable variation in the fitness of offspring and a mechanism for evolutionary changes to development. The marine annelid Streblospio benedicti provides an opportunity to study the effect of differences in maternal RNA provisioning on development because it is poecilogonous: there are two developmental pathways within a single species. Additionally, individuals of both developmental types can be reciprocally crossed to produce morphologically intermediate offspring. Using RNAseq and differential expression analysis, we explore how the two developmental morphs found in S. benedicti differ in maternal mRNA provisioning to eggs. We find that there are significant differences between the transcripts provided to oocytes of the different developmental morphs, including transcription and chromatin remodeling factors, indicating that maternal provisioning may explain some developmental differences. Comparing F₁ offspring of reciprocal crosses between developmental types, we determine the extent to which parent-of-origin effects influence maternal oocyte RNA provisioning. We find that F₁ mothers exhibit some differences in maternal RNA provisioning as well, raising the possibility that parental effects may influence their offspring’s provisioning.