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.
%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
}