title: Mass spectrometry and next-generation sequencing reveal an abundant and rapidly evolving abalone sperm protein.
abstract: Abalone, a broadcast spawning marine mollusk, is an important model for molecular interactions and positive selection in fertilization, but the focus has previously been on only two sperm proteins, lysin and sp18. We used genomic and proteomic techniques to bring new insights to this model by characterizing the testis transcriptome and sperm proteome of the Red abalone Haliotis rufescens. One pair of homologous, testis-specific proteins contains a secretion signal and is small, abundant, and associated with the acrosome. Comparative analysis revealed that homologs are extremely divergent between species, and show strong evidence for positive selection. The acrosomal localization and rapid evolution of these proteins indicates that they play an important role in fertilization, and could be involved in the species-specificity of sperm-egg interactions in abalone. Our genomic and proteomic characterization of abalone fertilization resulted in the identification of interesting, novel peptides that have eluded detection in this important model system for 20 years.
authors.affiliation: Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA 98195-5065, USA. mryner@uw.edu
authors.forename: Melody R
authors.initials: MR
authors.lastname: Palmer
authors.forename: Margo H
authors.initials: MH
authors.lastname: McDowall
authors.forename: Lia
authors.initials: L
authors.lastname: Stewart
authors.forename: Aleena
authors.initials: A
authors.lastname: Ouaddi
authors.forename: Michael J
authors.initials: MJ
authors.lastname: MacCoss
authors.forename: Willie J
authors.initials: WJ
authors.lastname: Swanson
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D049851:Gastropoda / Q000737:chemistry*; D020869:Gene Expression Profiling; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods; D008297:Male; D013058:Mass Spectrometry / Q000379:methods*; D008969:Molecular Sequence Data; D009088:Mucoproteins / Q000032:analysis* / Q000737:chemistry; D020411:Oligonucleotide Array Sequence Analysis; D010449:Peptide Mapping; D012313:RNA / Q000032:analysis; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA / Q000379:methods*; D013094:Spermatozoa / Q000737:chemistry; D013737:Testis / Q000737:chemistry; D059467:Transcriptome
chemical_list: D009088:Mucoproteins; D012313:RNA