title: Within-species divergence in the seminal fluid proteome and its effect on male and female reproduction in a beetle.
abstract: BACKGROUND
  Male seminal fluid proteins (SFPs), transferred to females during mating, are important reproductive proteins that have multifarious effects on female reproductive physiology and that often show remarkably rapid and divergent evolution. Inferences regarding natural selection on SFPs are based primarily on interspecific comparative studies, and our understanding of natural within-species variation in SFPs and whether this relates to reproductive phenotypes is very limited. Here, we introduce an empirical strategy to study intraspecific variation in and selection upon the seminal fluid proteome. We then apply this in a study of 15 distinct populations of the seed beetle Callosobruchus maculatus.
  
  
  RESULTS
  Phenotypic assays of these populations showed significant differences in reproductive phenotypes (male success in sperm competition and male ability to stimulate female fecundity). A quantitative proteomic study of replicated samples of male accessory glands revealed a large number of potential SFPs, of which ≥127 were found to be transferred to females at mating. Moreover, population divergence in relative SFP abundance across populations was large and remarkably multidimensional. Most importantly, variation in male SFP abundance across populations was associated with male sperm competition success and male ability to stimulate female egg production.
  
  
  CONCLUSIONS
  Our study provides the first direct evidence for postmating sexual selection on standing intraspecific variation in SFP abundance and the pattern of divergence across populations in the seminal fluid proteome match the pattern predicted by the postmating sexual selection paradigm for SFP evolution. Our findings provide novel support for the hypothesis that sexual selection on SFPs is an important engine of incipient speciation.
authors.affiliation: Animal Ecology, Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36, Uppsala, Sweden. julietagoenaga@aias.au.dk.|Aarhus Institute of Advanced Studies, Aarhus University, Høegh-Guldbergs Gade 6B, 11 8000, Aarhus C, Denmark. julietagoenaga@aias.au.dk.
authors.forename: Julieta
authors.initials: J
authors.lastname: Goenaga
authors.affiliation: Animal Ecology, Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36, Uppsala, Sweden. takya1122@gmail.com.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamane
authors.affiliation: Animal Ecology, Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36, Uppsala, Sweden. johanna.liljestrand-ronn@ebc.uu.se.
authors.forename: Johanna
authors.initials: J
authors.lastname: Rönn
authors.affiliation: Animal Ecology, Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36, Uppsala, Sweden. goran.arnqvist@ebc.uu.se.
authors.forename: Göran
authors.initials: G
authors.lastname: Arnqvist
mesh_terms: D000818:Animals; D005075:Biological Evolution; D001517:Coleoptera / Q000737:chemistry / Q000502:physiology*; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D019476:Insect Proteins / Q000032:analysis*; D008297:Male; D020543:Proteome / Q000032:analysis; D012098:Reproduction; D012641:Selection, Genetic; D012661:Semen / Q000737:chemistry; D029589:Seminal Plasma Proteins / Q000032:analysis*
chemical_list: D019476:Insect Proteins; D020543:Proteome; D029589:Seminal Plasma Proteins