Intellectual merit: All animals must reproducibly establish their body plan in the face of a constantly changing environment. Gurken is an evolutionarily conserved growth factor that is carefully regulated to establish the anterior / posterior and dorsal / ventral axis during oogenesis in the fruit fly Drosophila melanogaster. This project aims to identify the mechanisms by which the translation of Gurken is regulated by addressing the response of gurken mRNA to two stimuli: Nutrient limitation and DNA-damage. The first goal of the research is to understand how Drosophila maintain robust developmental patterning when confronted with an environment where the availability of nutrients is highly variable. The production of proteins is highly regulated in response to nutrient availability and ensures the efficient utilization of resources. Translation in the cell is globally repressed when nutrients are scarce; however, a small subset of essential proteins escape this repression by employing an alternative mechanism known as IRES-mediated translation. Preliminary work from the PI's lab suggests that the gurken mRNA utilizes this alternative mechanism to maintain the axis patterning when nutrients are limiting. The research will utilize a number of genetic and biochemical approaches to study the activity of the gurken mRNA both in vitro and in vivo. Specifically, the activity of regulatory regions of the gurken mRNA will be probed by joining them to light emitting luciferase reporter genes. This will facilitate the discovery of IRES elements that allow the oocyte to maintain its robust patterning. The second goal of the research is to understand how damage to the genome that occurs during meiosis affects the translation of gurken. Previous research has shown that mutations that interfere with DNA repair inhibit the translation of gurken by an unknown mechanism. Several novel mutations that affect this signaling pathway have been isolated. This project will take a genomic sequencing approach to identify these mutations and shed light on the mechanism(s) that communicates the integrity of the genome to developmental patterning molecules.
Broader Impact: The research conducted in this project will engage students in the study of translation regulation at the State University of New York College at Fredonia, a predominantly undergraduate institution. The research will address several pressing questions in the field, as indicated above, while allowing students to be the driving force behind the activities. The students will be intimately involved in the design and execution of the experiments and have the opportunity to present the results of the project at regional and national meetings. The research will directly impact not only the students working in the PI's laboratory, but also students that are enrolled in the core genetics lab and upper level molecular genetics lab courses (approximately 70 students per year). The project will facilitate full-time research experiences for three summer students that will be recruited from Fredonia and/or regional community colleges.
