PT  - JOURNAL ARTICLE
AU  - Heidi S. Fisher
AU  - Emily Jacobs-Palmer
AU  - Jean-Marc Lassance
AU  - Hopi E. Hoekstra
TI  - The genetic basis and fitness consequences of sperm midpiece size in deer mice
AID  - 10.1101/077826
DP  - 2016 Jan 01
TA  - bioRxiv
PG  - 077826
4099  - http://biorxiv.org/content/early/2016/09/27/077826.short
4100  - http://biorxiv.org/content/early/2016/09/27/077826.full
AB  - An extraordinary array of reproductive traits vary 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.