This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
Temperature-dependent sex determination (TSD) was first reported 40 years ago in an African lizard. It has since been shown that temperature determines sex in some fish and amphibians, several lizards, numerous turtles, and all crocodilians. Nevertheless, the mechanism underlying TSD is not known in any species. The goal of the proposed research is to dissect the molecular basis of TSD in the common snapping turtle, Chelydra serpentina. This will be accomplished by (1) sequencing all genes expressed in gonads from embryos incubated at male- and female-producing temperatures, (2) breeding adult turtles to study genetic influences on sex determination in their offspring, and (3) genetic analysis of gene expression profiles in a subset of offspring from the breeding study. This information will be integrated to identify the temperature-sensitive gene (or genes) responsible for TSD and to reveal the gene networks for testis and ovary development, which is basically the same in all vertebrates.
These experiments promise to get us closer to understanding the mechanism underlying TSD than has the previous 40 years of research. This work may provide new insight into the effects of climate change on endangered TSD species like sea turtles and a deeper understanding of sex determination in all vertebrates, including humans. Sequences for thousands of turtle genes could also be used for studies of other biological processes in turtles. Finally, this project will have a broader impact on education. Aspects of this research will be incorporated into undergraduate biology classes at UND. This represents a major advance in experiential learning of molecular biology for majors and non-majors. In addition, women, minorities, and North Dakota residents will be recruited into the PI?s laboratory, which will help increase the diversity of the nation?s scientists.
