title: The genetic basis and fitness consequences of sperm midpiece size in deer mice.
abstract: An extensive array of reproductive traits varies among species, yet the genetic mechanisms that enable divergence, often over short evolutionary timescales, remain elusive. Here we examine two sister-species of Peromyscus mice with divergent mating systems. We find that the promiscuous species produces sperm with longer midpiece than the monogamous species, and midpiece size correlates positively with competitive ability and swimming performance. Using forward genetics, we identify a gene associated with midpiece length: Prkar1a, which encodes the R1α regulatory subunit of PKA. R1α localizes to midpiece in Peromyscus and is differentially expressed in mature sperm of the two species yet is similarly abundant in the testis. We also show that genetic variation at this locus accurately predicts male reproductive success. Our findings suggest that rapid evolution of reproductive traits can occur through cell type-specific changes to ubiquitously expressed genes and have an important effect on fitness.
authors.affiliation: Department of Organismic &Evolutionary Biology, Department of Molecular &Cellular Biology, Museum of Comparative Zoology, Howard Hughes Medical Institute, Harvard University, 16 Divinity Ave, Cambridge, MA 02138, USA.
authors.forename: Heidi S
authors.initials: HS
authors.lastname: Fisher
authors.affiliation: Department of Organismic &Evolutionary Biology, Department of Molecular &Cellular Biology, Museum of Comparative Zoology, Howard Hughes Medical Institute, Harvard University, 16 Divinity Ave, Cambridge, MA 02138, USA.
authors.forename: Emily
authors.initials: E
authors.lastname: Jacobs-Palmer
authors.affiliation: Department of Organismic &Evolutionary Biology, Department of Molecular &Cellular Biology, Museum of Comparative Zoology, Howard Hughes Medical Institute, Harvard University, 16 Divinity Ave, Cambridge, MA 02138, USA.
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Lassance
authors.affiliation: Department of Organismic &Evolutionary Biology, Department of Molecular &Cellular Biology, Museum of Comparative Zoology, Howard Hughes Medical Institute, Harvard University, 16 Divinity Ave, Cambridge, MA 02138, USA.
authors.forename: Hopi E
authors.initials: HE
authors.lastname: Hoekstra
mesh_terms: D000818:Animals; D005786:Gene Expression Regulation / Q000502:physiology; D056084:Genetic Fitness; D005838:Genotype; D008297:Male; D010542:Peromyscus / Q000235:genetics* / Q000502:physiology; D040641:Quantitative Trait Loci; D013045:Species Specificity; D013094:Spermatozoa / Q000502:physiology*