Molecular Adaptation and Gametic Competition

Pennsylvania State Univ University Park, University Park PA

Investigators

Abstract

This project examines the role that accessory gland proteins play in fertilization, particularly in the context of gametic competition. It is known that these proteins play a pivotal role in sperm success, because Drosophila (fruit flies) mutants that lack the ability to produce accessory gland proteins have much reduced fertility. These mutants also exhibit characteristics that suggest that accessory gland proteins are particularly important in the sequestration and storage of sperm by females. In insects, normal females may store sperm from a single mating for several weeks, an attribute that is particularly important for sparsely distributed animals. Genomic methods are being employed to identify all of the genes encoding accessory gland proteins, and comparison of the DNA sequences of related species will allow identification of which parts of the molecules are evolving most rapidly. In addition within-species polymorphism in the Acp genes will be assessed and tested for its association with variation in gametic competitive ability. This project is a renewal and extension of a project that received prior support from NSF, and it has served as a vehicle for training and education of many students. Seven undergraduates have worked in the laboratory directly on this project, and 3 have become co-authors on publications. Postdoctoral fellow Alberto Civetta secured a faculty position at the University of Manitoba on the basis of the work he did on the project. In the coming years, student involvement will continue to be vital. The method of constructing a cDNA library and aligning multiple random genes of species X with known sequences of species Y, devised under the past NSF support, has received widespread attention as a means to exhaustively identify genes expressed in specific tissues and simultaneously to identify those that are undergoing the most rapid turnover.