Discordant phylogeographic patterns between the Y chromosome and mitochondrial DNA in the house mouse: selection on the Y chromosome?
We have compared patterns of geographic variation and molecular divergence of mitochondrial DNA (mtDNA) and Y chromosome over the range of the different subspecies of Mus musculus. MtDNA was typed for 305 nucleotides in the control region, the Y chromosome for 834 base pairs (bp) in Zfy introns and 242 bp in Sry, a Zfy2 18-bp deletion, and two microsatellites. Apparent discrepancies exist between the distributions of the lineages of mtDNA and of the two major Y-chromosome lineages thus defined: some subspecies share the same mtDNA lineage but have different Y-chromosome lineages or vice versa. One microsatellite reveals a geographically clustered variation inside the distribution of each Y-chromosome lineage, showing that new Y-chromosome variants can rapidly spread locally. The two major Y-chromosome lineages have a divergence time only about one fourth of that between mtDNA lineages. Although this recent coalescence of the Y chromosomes between subspecies could partly be due to a lower ancestral polymorphism of the Y chromosome, it suggests that secondary introgression after the radiation of the subspecies might have occurred. There is evidence that the differentiation of the Y-chromosome lineages contributes to partial reproductive isolation between subspecies, and patterns of molecular evolution suggest that selection has played a role in the rapid spread across subspecies.
Boissinot
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S
Laboratoire Génome et Populations (CNRS UPR 9060), Université Montpellier II, France.
Boursot
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P
D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D004272:DNA, Mitochondrial; D004268:DNA-Binding Proteins / Q000235:genetics; D014644:Genetic Variation; D007438:Introns; D008297:Male; D051379:Mice / Q000145:classification / Q000235:genetics*; D018895:Microsatellite Repeats; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D010802:Phylogeny; D012689:Sequence Homology, Nucleic Acid; D051876:Sex-Determining Region Y Protein; D014157:Transcription Factors; D014998:Y Chromosome
D004272:DNA, Mitochondrial; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D051876:Sex-Determining Region Y Protein; C497746:Sry protein, mouse; D014157:Transcription Factors; C501343:Zfy2 protein, mouse