When Genomics meets Proteomics: The Effects of Mating Strategies on Primate Reproductive Protein Evolution

The intersection between genomics and proteomics is greater than ever before. With genome sequences and de novo assembly from RNA sequences of an increasing array of organisms, it is now possible to characterize the protein composition and abundances from individual cell-types, organs, and other systems using high-throughput shotgun proteomics. We used a unique combination of these technologies to study the evolution of seminal fluid proteins (Sfps) in human and non-human primates. Sexual selection has long been hypothesized to act on primate reproductive characters; sperm size, ejaculate volume, and testes sizes have all been positively correlated with promiscuous mating systems in primates. While reproductive genes are some of the most rapidly evolving genes in the genome, there is no conclusive evidence that a correlation between different mating systems and the rapid evolution of Sfps exists. We hypothesized that Sfps important to multi-male mating species evolve faster and are more abundant than in primate species that are uni-male maters. We used shotgun proteomics to identify and quantify a large proportion of uncharacterized Sfps from the diverse mating systems of 8 primate lineages. Overall, our proteomic data shows that there is a vast repertoire of proteins in seminal fluid, and we confirm that primate Sfps are evolving much more rapidly than the genome-wide average. We are using regression and Bayesian models to test for correlations between evolutionary rates, protein abundances, and mating systems, and are undertaking a comprehensive search for genes that have been lost in specific lineages coincident with mating system evolution.