Poster Presentation Society for Molecular Biology and Evolution Conference 2016

Evolution of parent-of-origin effects on complex traits (#599)

Ge Zhang 1
  1. Cincinnati Children's Hospital Medical Center, Cincinnati, OHIO, United States

Parent-of-origin effects, in which the expression of phenotype effect of an allele depends on its parental origin, have been observed in many complex traits. Many theories have been proposed to explain the evolutionary origin of parent-of-origin effects. In this study, I examine the evolutionary advantage of parent-of-origin effects using a quantitative genetics model. I consider a quantitative trait under stabilizing selection is influenced by a large number of loci with various degree of unequal expression depending on their parent of origin. I evaluate the adaptive advantage of different parent-of-origin dependent expression patterns of these loci under various selection scenarios using forward-time population genetics simulation. The results show that when there is a positive parental effect, selection favors expression of alleles inherited from the opposite parent. If resemblance between mothers (or fathers) and offspring increases fitness, selection favors expression of alleles from the same parent. Parent-offspring conflict favors bilateral parent-of-origin expression of alleles, with some loci preferentially expressing the maternal alleles and some expressing the paternal alleles. If the strength of selection on maternal alleles is larger than paternal alleles, then better mean fitness is achieved when there are more loci with high expression of paternal alleles. In addition, these selection scenarios only favor strong parent-of-origin effects in a fraction of trait influencing loci. This study indicates that some complex traits loci might have acquired parent-of-origin dependent expression through different evolutionary pathways.