RT Journal Article
SR Electronic
T1 Sex-dependent dominance at a single locus maintains variation in age at maturity in Atlantic salmon
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 024695
DO 10.1101/024695
A1 Nicola J. Barson
A1 Tutku Aykanat
A1 Kjetil Hindar
A1 Matthew Baranski
A1 Geir H. Bolstad
A1 Peder Fiske
A1 Céleste Jacq
A1 Arne J. Jensen
A1 Susan E. Johnston
A1 Sten Karlsoon
A1 Matthew Kent
A1 Eero Niemelä
A1 Torfinn Nome
A1 Tor F. Næsje
A1 Panu Orell
A1 Atso Romakkaniemi
A1 Harald Sægrov
A1 Kurt Urdal
A1 Jaakko Erkinaro
A1 Sigbjørn Lien
A1 Craig R Primmer
YR 2015
UL http://biorxiv.org/content/early/2015/08/17/024695.1.abstract
AB Males and females share many traits that have a common genetic basis, however selection on these traits often differs between the sexes leading to sexual conflict1,2. Under such sexual antagonism, theory predicts the evolution of genetic architectures that resolve this sexual conflict2-6. Yet, despite intense theoretical and empirical interest, the specific genetic loci behind sexually antagonistic phenotypes have rarely been identified, limiting our understanding of how sexual conflict impacts genome evolution4,7,8 and the maintenance of genetic diversity8,9. Here, we identify a large effect locus controlling age at maturity in 57 salmon populations, an important fitness trait in which selection favours earlier maturation in males than females10, and show it is a clear example of sex dependent dominance reducing intralocus sexual conflict and maintaining adaptive variation in wild populations. Using high density SNP data and whole genome re-sequencing, we found that vestigial-like family member 3 (VGLL3) exhibits sex-dependent dominance in salmon, promoting earlier and later maturation in males and females, respectively. VGLL3, an adiposity regulator associated with size and age at maturity in humans, explained 39.4% of phenotypic variation, an unexpectedly high effect size for what is usually considered a highly polygenic trait. Such large effects are predicted under balancing selection from either sexually antagonistic or spatially varying selection11-13. Our results provide the first empirical example of dominance reversal permitting greater optimisation of phenotypes within each sex, contributing to the resolution of sexual conflict in a major and widespread evolutionary trade-off between age and size at maturity. They also provide key empirical evidence for how variation in reproductive strategies can be maintained over large geographical scales. We further anticipate these findings will have a substantial impact on population management in a range of harvested species where trends towards earlier maturation have been observed.