Dissertation Research: Phylogenetic Inference from Bryozoan Hox Genes

Woods Hole Oceanographic Institution, Woods Hole MA

Investigators

Abstract

This project will investigate the evolutionary origin of bryozoans, a group of aquatic animals with many species that form colonies by asexual reproduction. Although association of bryozoans with molluscs, annelids, and other protostome taxa is well supported, relationships among these groups is not. Data suggesting that bryozoans diverged from a common ancestor before other members of the clade Lophotrochozoa is, however, intriguing and warrants further investigation. The present study will investigate Hox genes, which are important transcription factors in early development. The DNA sequence of Hox genes, as well as their arrangement within the genome, has been conserved over the course of animal evolution, making them good candidates for understanding relationships between widely divergent groups of animals. DNA sequencing and gene mapping will be utilized to investigate the Hox genes of representatives from two major lineages of bryozoans, cheilostomes and phylactolaemates. These data will be combined with other information to infer the relationships between bryozoans and other major lineages of animals. Results of this study will provide important information concerning the early evolution of animal development and body plans. Additionally, the sequencing and mapping of bryozoan Hox genes will provide a platform for future work on the origins of zooid polymorphism in bryozoan colonies.