GENETIC-VARIATION AND PHYLOGEOGRAPHY OF CENTRAL-ASIAN AND OTHER HOUSEMICE, INCLUDING A MAJOR NEW MITOCHONDRIAL LINEAGE IN YEMEN

The mitochondrial DNA (mtDNA) control region and flanking tRNAs were s equenced from '76 mice collected at 60 localities extending from Egypt through Turkey, Yemen, Iran, Afghanistan, Pakistan, and Nepal to east ern Asia. Segments of the Y chromosome and of a processed p53 pseudoge ne (Psi p53) were amplified from many of these mice and from others co llected elsewhere in Eurasia and North Africa. The 251 mtDNA types, in cluding 54 new ones reported here, now identified from commensal house mice (Mus musculus group) by sequencing this segment can be organized into four major lineages-domesticus, musculus, castaneus, and a new l ineage found in Yemen. Evolutionary tree analysis suggested the domest icus mtDNAs as the sister group to the other three commensal mtDNA lin eages and the Yemeni mtDNAs as the next eldest lineage. Using this tre e and the phylogeographic approach, we derived a new model for the ori gin and radiation of commensal house mice whose main features are an o rigin in west-central Asia (within the present-day range of M. domesti cus) and the sequential spreading of mice first to the southern Arabia n Peninsula, thence eastward and northward into south-central Asia, an d later from south-central Asia to north-central Asia (and thence into most of northern Eurasia) and to southeastern Asia. Y chromosomes wit h and without an 18-bp deletion in the Zfy-2 gene were detected among mice from Iran and Afghanistan, while only undeleted Ys were found in Turkey, Yemen, Pakistan, and Nepal. Polymorphism for the presence of a Psi p53 was observed in Georgia, Iran, Turkmenistan, Afghanistan, and Pakistan. Sequencing of a 128-bp Psi p53 segment from 79 commensal mi ce revealed 12 variable sites and implicated greater than or equal to 14 alleles. The allele that appeared to be phylogenetically ancestral was widespread, and the greatest diversity was observed in Turkey. Afg hanistan, Pakistan, and Nepal. Two mice provided evidence for a second Psi p53 locus in some commensal populations.