Intratetrad mating and the evolution of linkage relationships

Evolution. 2004 Apr;58(4):702-9. doi: 10.1111/j.0014-3820.2004.tb00403.x.


Mating among the immediate products of meiosis (intratetrad mating) is a common feature of many organisms with parthenogenesis or with mating-type determination in the haploid phase. Using a three-locus deterministic model we show that intratetrad mating, unlike other systems of mating, allows sheltering of deleterious recessive alleles even if there is only partial linkage between a mating locus and a load locus. Moreover, modifiers that reduce recombination between the load and mating-type locus will spread to fixation, even when there is no linkage disequilibrium between these loci in the population as a whole. This seeming contradiction to classical expectation is because partial linkage generates linkage disequilibrium among segregating loci within a tetrad, which then acts as the "mating unit."

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Alleles*
  • Computer Simulation
  • Heterozygote
  • Meiosis / genetics*
  • Models, Genetic*
  • Mutation / genetics*
  • Reproduction / genetics
  • Selection, Genetic*