Begun DJ, et al. Betran E, et al. A sex-ratio suppressor, Nmy not much yangand its corresponding X-linked sex-ratio distorters, Dox distorter on the X and MDox Mother of Doxwere identified by fine mapping and positional cloning [ 5051 ].
This assumption derives from the fact that hybrid incompatibilities require functional evolutionary substitutions [ 6566 ], and natural selection fixes beneficial mutations much faster than drift will fix neutral or deleterious ones.
The sex-ratio suppressing function of Nmy requires a pair of inverted repeats of bp [ 51 ]. Dynamic changes in Rad51 distribution on chromatin during meiosis in male and female vertebrates. As with both mammals and worms, the chicken Z and W chromosomes are substrates for the meiotic recombination machinery Schoenmakers et al.
Haldane's rule genetic conflict and sex chromosome evolution games in Erie X-chromosome size in Drosophila. Both the distorters and the suppressors are polymorphic across populations of D. The genetic basis of Haldane's rule. Molecular aspects of XY body formation.
Here we focus on the meiotic behavior of heteromorphic sex chromosomes in three species: nematodes Caenorhabditis eleganswhere males have a single X chromosome that completely lacks a pairing partner, mammals Mus musculuswhere males have heterologous X and Y chromosomes with only discrete regions of homology, and birds Gallus galluswhere females are the heterogametic sex with Z and Genetic conflict and sex chromosome evolution games in Erie chromosomes, which are also largely non-homologous Figure 1.
Genetics and the Origin of Species. In organisms with separate sexes, parents maximize their fitness by investing equally in both sexes. To ensure that each gamete receives the correct complement of DNA, a highly orchestrated program of nuclear events occurs Figure 2A.
First, some de novo genes with testis-specific expression might be segregation distorters. Sex-dependent gene expression and evolution of the Drosophila transcriptome.
Genetics of postzygotic isolation and Haldane's rule in haplodiploids. This in turn favors suppressors of the distorter that arise on an autosome or the other sex chromosome [ 15 , 16 ]. Turner JM. Sex-dependent gene expression and evolution of the Drosophila transcriptome.
The invasion probability of a newly evolved sex-ratio distorter is therefore determined solely by its transmission advantage and any deleterious effects it has on its host, and is not influenced by the population sex ratio. Empirical evidence from Drosophila and mice strongly support the large X-effect.