The proteins on the surface of eggs and sperm determine which males can reproduce with which females, and often define whether one species is distinct from another. Little is known about why these proteins evolve quickly in some species, but not in others. The PIs propose to 1) document the variation in these proteins in eggs and sperm of one sea urchin species with rapidly evolving sperm proteins and one species with slowly evolving sperm proteins, 2) determine how each protein variant performs in the laboratory and under natural conditions in the sea, and 3) investigate the relationship between changes in egg proteins with changes in sperm proteins.
In addition to uncovering what makes fertilization possible among some individuals but not others, this work combines two disciplines to explore when and how ecological processes that determine when novel proteins will be more successful can drive evolution. The computational methods developed will allow analysis of how changes in one part of the genome can influence changes in another part, and will be of general use for deciphering the flood of incoming genomic data. Undergraduate and graduate students, particularly those from underrepresented groups, will be trained in molecular biology, field ecology and computational science. Software developed here will be made publicly available.