Meeting Abstract

96.6  Sunday, Jan. 6  Identifying genomic regions responsible for offspring dimorphism in Streblospio benedicti ZAKAS, C*; ROCKMAN, M.V.; New York University; New York University christinazakas@gmail.com

Major transitions between development modes are a nearly ubiquitous feature in the evolutionary history of most animal phyla, with profound micro- and macroevolutionary consequences. However, the genetic changes that govern such transitions have yet to be characterized, impairing our understanding of how such shifts occur and shape metazoan evolution. Poecilogonous species, such as the marine polychaete Streblospio benedicti, produce two distinct offspring types and are ideal systems to study the evolutionary consequences of offspring dimorphism within a single species. Here, we use transcriptomic data to investigate how intraspecific genetic differences can produce morphologically distinct offspring modes. We compare expression and sequence differences between adults with contrasting developmental modes to establish markers for future genomic studies. Preliminary investigation of the S. benedicti transcriptome has revealed little differentiation between the two developmental modes in neutral SNP markers, suggesting that only a small portion of the genome underlies developmental differences. By using a comparative transcriptomic approach, we expect to identify a small number of key gene regions that are responsible for driving the distinct morphological differences in development mode that occurs in S. benedicti.