title: Selection at the Y chromosome of the African buffalo driven by rainfall.
abstract: Selection coefficients at the mammalian Y chromosome typically do not deviate strongly from neutrality. Here we show that strong balancing selection, maintaining intermediate frequencies of DNA sequence variants, acts on the Y chromosome in two populations of African buffalo (Syncerus caffer). Significant correlations exist between sequence variant frequencies and annual rainfall in the years before conception, with five- to eightfold frequency changes over short time periods. Annual rainfall variation drives the balancing of sequence variant frequencies, probably by affecting parental condition. We conclude that sequence variants confer improved male reproductive success after either dry or wet years, making the population composition and dynamics very sensitive to climate change. The mammalian Y chromosome, interacting with ecological processes, may affect male reproductive success much more strongly than previously thought.
authors.affiliation: Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa. pim.vanhooft@wur.nl
authors.forename: Pim
authors.initials: P
authors.lastname: van Hooft
authors.forename: Barend J
authors.initials: BJ
authors.lastname: Greyling
authors.forename: Herbert H T
authors.initials: HH
authors.lastname: Prins
authors.forename: Wayne M
authors.initials: WM
authors.lastname: Getz
authors.forename: Anna E
authors.initials: AE
authors.lastname: Jolles
authors.forename: Armanda D S
authors.initials: AD
authors.lastname: Bastos
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D002020:Buffaloes / Q000235:genetics*; D004463:Ecology; D005787:Gene Frequency; D014644:Genetic Variation; D006239:Haplotypes; D008297:Male; D008957:Models, Genetic; D011110:Polymorphism, Genetic; D011891:Rain; D012641:Selection, Genetic; D020080:Tandem Repeat Sequences; D014998:Y Chromosome / Q000235:genetics*