Germ cells are the only cells that produce the sperm and eggs required for sexual reproduction. Proper germline development is, therefore, critical for survival of the next generation. Two important steps in this process are the decision made by germ cells to develop as male or female so they produce either sperm or eggs, and the ability of these cells to develop into functional germline stem cells required for continuous gamete production. However, relatively little is know about the cellular and molecular mechanism regulating these processes. Through genetic and molecular analyses in the fruit fly, Drosophila melanogaster, the Wawersik lab is working to define these mechanisms. As the basic process of germ cell development is remarkably similar in flies, mice and even humans, they expect that better understanding of these mechanisms will help determine how defects in germ cell development can cause infertility and germ cell tumors. Thus, work by the Wawersik lab has important implications for patients suffering from cancer and infertility. Furthermore, since this work is being performed by a research team at a primarily undergraduate institution, these studies provide an exciting and highly relevant backdrop to teach fundamental aspects of genetics, as well as cellular, molecular and developmental biology to the next generation of American scientists.
The overall goal of this project was to determine how germ cells that are required for the production of sperm or eggs determine whether to develop as male or female, and to ascertain how stem cells required for continued production of sperm and eggs first form. A broader focus of this work is to train the next generation of scientists and help high school teachers gain exposure to research so that they can foster the development of future scientists prior to college. As part of these goals, 31 undergraduate students, 1 graduate student, 2 high school teachers and 5 high school students have had the opportunity for intensive research training on research projects related to this grant. Research students have been integrally involved in the collection of data for scientific papers that are published or in preparation. Teachers have also developed genetics lab curricula based on their research experiences on this project that have now been deployed in AP biology courses. Findings from research projects performed as part of this project have shown that female germ cells in the fruit fly, Drosophila melanogaster, actively repress genes that promote male fate; failure to repress these genes causes infertility and the formation of germ cell tumors that may be similar to germ cell tumors (called teratomas) that are found in humans. Additionally, data have characterized the process of stem cell development in Drosophila testes. Research with adult Drosophila testes has uncovered fundamental paradigms in regulation of stem cell behavior that also function in human stem cells systems. Therefore, we anticipate that our current and future studies in Drosophila will lead to a better understanding of the role for stem cells during organ formation as well as an understanding of how defects in stem cell development lead to human developmental disorders.
