RESUMEN
Advances in mass spectrometry technology, high-throughput proteomics and genome annotations have resulted in significant increases in our molecular understanding of sperm composition. Using improved separation and detection methods and an updated genome annotation, a re-analysis of the Drosophila melanogaster sperm proteome (DmSP) has resulted in the identification of 956 sperm proteins. Comparative analysis with our previous proteomic dataset revealed 766 new proteins and an updated sperm proteome containing a total of 1108 proteins, termed the DmSP-II. This expanded dataset includes additional proteins with predicted sperm functions and confirms previous findings concerning the genomic organization of sperm loci. Bioinformatic and protein network analyses demonstrated high quality and reproducibility of proteome coverage across three replicate mass spectrometry runs. The use of whole-cell proteomics in conjunction with characterized phenotypes, functional annotations and pathway information has advanced our systems level understanding of sperm proteome functional networks.
Asunto(s)
Proteínas de Drosophila/análisis , Drosophila melanogaster , Proteoma/análisis , Proteómica/métodos , Espermatozoides/metabolismo , Animales , Cromatografía Líquida de Alta Presión , Bases de Datos de Proteínas , Proteínas de Drosophila/química , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Genoma de los Insectos , Masculino , Espectrometría de Masas , Fenotipo , Proteoma/química , Proteoma/genética , Proteoma/metabolismo , Espermatozoides/químicaRESUMEN
Spermatozoa are a focal point for the impact of sexual selection due to sperm competition and sperm-female interactions in a wide range of sexually reproducing organisms. In-depth molecular investigation of the ramifications of these selective regimes has been limited due to a lack of information concerning the molecular composition of sperm. In this study, we utilize three previously published proteomic data sets in conjunction with our whole mouse sperm proteomic analysis to delineate cellular regions of sperm most impacted by positive selection. Interspecific analysis reveals robust evolutionary acceleration of sperm cell membrane genes (which include genes encoding acrosomal and sperm cell surface proteins) relative to other sperm genes, and evidence for positive selection in approximately 22% of sperm cell membrane components was obtained using maximum likelihood models. The selective forces driving the accelerated evolution of these membrane proteins may occur at a number of locations during sperm development, maturation, and transit through the female reproductive tract where the sperm cell membrane and eventually the acrosome are exposed to the extracellular milieu and available for direct cell-cell interactions.