Fixed nucleotide differences on the Y chromosome indicate clear divergence between Equus przewalskii and Equus caballus.
The phylogenetic relationship between Equus przewalskii and E. caballus is often a matter of debate. Although these taxa have different chromosome numbers, they do not form monophyletic clades in a phylogenetic tree based on mtDNA sequences. Here we report sequence variation from five newly identified Y chromosome regions of the horse. Two fixed nucleotide differences on the Y chromosome clearly display Przewalski's horse and domestic horse as sister taxa. At both positions the Przewalski's horse haplotype shows the ancestral state, in common with the members of the zebra/ass lineage. We discuss the factors that may have led to the differences in mtDNA and Y-chromosomal observations.
Wallner
B
B
Institut für Tierzucht und Genetik, Veterinärmedizinische Universität Wien, Veterinärplatz, Wien, Austria. wallner@i122server.vu-wien.ac.at
Brem
G
G
Müller
M
M
Achmann
R
R
D000818:Animals; D001483:Base Sequence; D004272:DNA, Mitochondrial / Q000235:genetics; D014644:Genetic Variation / Q000235:genetics*; D006736:Horses / Q000145:classification / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D011336:Probability; D013045:Species Specificity; D014998:Y Chromosome / Q000235:genetics*
D004272:DNA, Mitochondrial