Comparative transcriptomics of caste development across multiple origins of eusociality
Michael R Warner, Michael R Warner , Alexander S. Mikheyev , Timothy A. Linksvayer
University of Pennsylvania; University of Pennsylvania ; Okinawa Institute of Science and Technology ; University of Pennsylvania
Reproductive division of labor via caste has evolved many times in insects and is responsible for the immense ecological success of social insects. It has been hypothesized that there exists a core set of genes associated with each origin of reproductive caste, but studies have largely failed to identify such a core set. Here, we present the most comprehensive transcriptomic comparison to date of caste development across multiple origins of eusociality. We perform RNA-sequencing across development of queens and workers in the honey bee Apis mellifera and ant Monomorium pharaonis. We seek to identify a core set of genes commonly associated with caste development in each species, which we term a caste toolkit. We test if this caste toolkit, and a related social toolkit derived from comparisons between nurses and foragers, is rooted in common core developmental processes. This study will provide a foundation with which to test whether convergent molecular mechanisms underlie key innovations associated with the repeated evolution of eusociality.