%0 Journal Article %1 turelli2000dominance %A Turelli, Michael %A Orr, H. Allen %D 2000 %K DMI Haldanes_rule dominance epistasis genetic_architecture incompatibilities interactions speciation theory %N 4 %P 1663--1679 %T Dominance, Epistasis and the Genetics of Postzygotic Isolation %U http://www.genetics.org/content/154/4/1663.long %V 154 %X The sterility and inviability of species hybrids can be explained by between-locus “Dobzhansky-Muller” incompatibilities: alleles that are fit on their “normal” genetic backgrounds sometimes lower fitness when brought together in hybrids. We present a model of two-locus incompatibilities that distinguishes among three types of hybrid interactions: those between heterozygous loci (H 0 ), those between a heterozygous and a homozygous (or hemizygous) locus (H 1 ), and those between homozygous loci (H 2 ). We predict the relative fitnesses of hybrid genotypes by calculating the expected numbers of each type of incompatibility. We use this model to study Haldane’s rule and the large effect of X chromosomes on postzygotic isolation. We show that the severity of H 0 vs. H 1 incompatibilities is key to understanding Haldane’s rule, while the severity of H 1 vs. H 2 incompatibilities must also be considered to explain large X effects. Large X effects are not inevitable in backcross analyses but rather—like Haldane’s rule—may often reflect the recessivity of alleles causing postzygotic isolation. We also consider incompatibilities involving the Y (or W) chromo- some and maternal effects. Such incompatibilities are common in Drosophila species crosses, and their consequences in male- vs. female-heterogametic taxa may explain the pattern of exceptions to Haldane’s rule.

@article{turelli2000dominance, abstract = {The sterility and inviability of species hybrids can be explained by between-locus “Dobzhansky-Muller” incompatibilities: alleles that are fit on their “normal” genetic backgrounds sometimes lower fitness when brought together in hybrids. We present a model of two-locus incompatibilities that distinguishes among three types of hybrid interactions: those between heterozygous loci (H 0 ), those between a heterozygous and a homozygous (or hemizygous) locus (H 1 ), and those between homozygous loci (H 2 ). We predict the relative fitnesses of hybrid genotypes by calculating the expected numbers of each type of incompatibility. We use this model to study Haldane’s rule and the large effect of X chromosomes on postzygotic isolation. We show that the severity of H 0 vs. H 1 incompatibilities is key to understanding Haldane’s rule, while the severity of H 1 vs. H 2 incompatibilities must also be considered to explain large X effects. Large X effects are not inevitable in backcross analyses but rather—like Haldane’s rule—may often reflect the recessivity of alleles causing postzygotic isolation. We also consider incompatibilities involving the Y (or W) chromo- some and maternal effects. Such incompatibilities are common in Drosophila species crosses, and their consequences in male- vs. female-heterogametic taxa may explain the pattern of exceptions to Haldane’s rule.}, added-at = {2017-08-08T07:25:18.000+0200}, author = {Turelli, Michael and Orr, H. Allen}, biburl = {https://www.bibsonomy.org/bibtex/25fa2c36a833263a433d5984edfbe50f5/peter.ralph}, interhash = {28bf46f0ee19438f09df5e4be3a41e9e}, intrahash = {5fa2c36a833263a433d5984edfbe50f5}, keywords = {DMI Haldanes_rule dominance epistasis genetic_architecture incompatibilities interactions speciation theory}, number = 4, pages = {1663--1679}, timestamp = {2017-08-08T07:25:18.000+0200}, title = {Dominance, Epistasis and the Genetics of Postzygotic Isolation}, url = {http://www.genetics.org/content/154/4/1663.long}, volume = 154, year = 2000 }