microRNAs and Metazoan Evolution

Dartmouth College, Hanover NH

Investigators

Abstract

One of the enduring puzzles surrounding the ""Cambrian explosion"" is the rapid evolution of highly disparate and complex animal body plans. The fossil record sheds no light on the underlying molecular mechanisms governing body-plan evolution itself. This study will address the question of how morphological complexity arose during animal evolution. This research focuses on non-coding genes, specifically, microRNAs, which are non-coding RNA molecules that negatively regulate the expression of protein-coding genes. The research will document the microRNA complements of several metazoan taxa and then determine the spatial expression profiles for a subset of these newly discovered molecules. MicroRNAs may have played a profound role in both the origin and subsequent constraint of animal body plans, and thus a detailed study of microRNA evolution is necessary to understand their role in morphological complexity and phylogeny. Patterns of microRNA evolution may also provide new evidence for evolutionary relationships among major groups of animals. This study has the potential to provide important new insights into the evolution of body plans in animals and a better biological understanding of the explosive diversification of animals that is seen in the Cambrian fossil record. Training students to approach such classic paleontological and anatomical problems with modern molecular means, specifically focusing on the non-coding component of the animalian genome, will give them the necessary tools to simultaneously discover both the pattern and processes associated with animalian macroevolution.