RUI: Understanding the role of duplicate Hox genes in the evolution of novelty by investigating patterns of molecular evolution and functional divergence in a basal ray-finned fish

San Francisco State University, San Francisco CA

Investigators

Abstract

One of the most intriguing topics in evolutionary biology is the question of what types of genetic changes are responsible for generating phenotypic diversity. The central hypothesis that will be tested in this project is that gene duplication has played an important role in the evolution of novel features in vertebrates, more specifically in the elongated rostrum in the paddlefish. The American paddlefish makes its living in the murky waters of the Mississippi River Basin with its elongated rostrum - an exaggerated novel feature with electrosensory capabilities. This charismatic organism belongs to an order with a dynamic genome duplication history, and data indicate that an independent genome duplication occurred in paddlefish. Gene duplication is regarded as the predominant mechanism by which genes with new functions and associated phenotypic novelties arise, but the evolutionary processes contributing to the initial retention of duplicate genes are not well understood. A family of genes called Hox genes have been implicated in the evolution of body plan features. However previous studies on Hox gene expression during rostrum and fin development in fish have not taken this into account. This project will examine various aspects of the molecular evolution and functional divergence of duplicated Hox genes in paddlefish. The proposed work is significant because it identifies genetic pathways associated with the evolution of novel structures, via maintenance of duplicate genes in the most diverse vertebrate group, ray-finned fishes. This work has important and broad impacts because it contributes to the training of underrepresented minority and female students at San Francisco State University, a primarily undergraduate institution that serves large numbers of minority students. In addition, the results of this research will be infused into the undergraduate curricula at San Francisco State.