RUI: Investigating Hox gene regulation of paired appendage patterning in the basal actinopterygian, Polyodon

Kennesaw State University Research And Service Foundation, Kennesaw GA

Investigators

Abstract

Terrestrial (land living) vertebrates possess a specialized region of their appendages called the autopod (hands & feet; fingers & toes) which are not present in their aquatic fish ancestors. Variation in key genes that form the autopod generate the diversity of crawling, flying, and swimming adaptations we see in nature, but also explain common forms of congenital birth defects seen in human hands and feet. Previously, this laboratory discovered that genes involved in autopod formation, called Hox genes, are active in the fins of a primitive living fish, the North American paddlefish Polyodon spathula. This fish does not have an autopod region, nor did it evolve from an ancestor that had an autopod. Why then, do paddlefish have these genes and what is their function? To address these questions, these investigators are using modified versions of these genes designed to either shut down gene function or amplify it above normal levels within the developing fins of embryonic paddlefish. These results should reveal the normal function of these genes, and interpret the results of abnormal gene expression in comparison to data from human and mouse birth defects. Initial results demonstrate a pattern of loss of skeletal structures that links specific Hox genes to the formation of specific portions of the fin, in a manner similar to humans and mice. These results will provide significant insights into autopod formation that will answer both evolutionary questions and contribute to clinical approaches for addressing congenital autopod birth defects in humans. In addition, undergraduates at Kennesaw State will comprise the core of this research, providing numerous students with research experience to prepare them for careers in medicine and the biological sciences.