Tracing the eastward dispersal of the house mouse, Mus musculus

Abstract

Here we describe recent advances in our understanding of the natural history of the house mouse, Mus musculus, with a focus on the genetic characteristics of the home territories and how this relates to prehistoric eastward movements from the predicted source areas. Recent studies of mitochondrial and nuclear gene sequences provide insight into the ancient divergence of the three subspecies groups, M. m. castaneus (CAS), M. m. domesticus (DOM), and M. m. musculus (MUS), with inferred natural habits (homelands) in central (Iran, Afghanistan, Pakistan, and India), western (western Iran), and northern (central Asia) areas, respectively. Our mitochondrial DNA and nuclear gene analyses indicate that only one local lineage of CAS extended its range via historical rapid expansion at two different times to Southeast Asia and East Asia, including Japan and southern Sakhalin. This is suggestive of a rapid range expansion of CAS out of its homeland, perhaps associated with the spread of agricultural practices in Asia. The subspecies group MUS now occurs in a large portion of northern Eurasia from eastern Europe in the West to the Japanese Islands in the East, including Uzbekistan, Kazakhstan, southern Siberia, northern China, and Korea, showing divergent patterns in terms of Mus musculus genetics, particularly in relation to nuclear gene sequences, allozymes (e.g., hemoglobin), morphological characteristics, and cytogenetic C-banding patterns. In this review article, we explain the complex spatial patterns of MUS. We postulate that two historical dispersal events took place, from two different source areas, and tentatively assign the taxon names “musculus” and “wagneri” to the two populations, which are associated with distinct genetic modules.

A comparison of immunoglobulin IGHV, IGHD and IGHJ genes in wild‐derived and classical inbred mouse strains

“…Other subspecies of M. m. musculus probably exist, and a number have been proposed, such as M. m. bactrianus and M. m. gentilulus. 36,37 The divergence patterns of the IGH loci of the mouse strains reported here can be considered in the context of the allelic diversity that has been reported in humans. For example, a comparison of the two published fully sequenced human IGHV haplotypes revealed that, of the 68 nonredundant functional/ORF IGHV sequences identified across the two haplotypes, only 22 were observed in both, accounting for both allelic and structural variants.…”

“…It is also possible that the IGH loci of these strains include haplotype blocks derived from other lineages of the house mouse, or even from other Mus species such as M. spretus . Other subspecies of M. m. musculus probably exist, and a number have been proposed, such as M. m. bactrianus and M. m. gentilulus …”

A comparison of immunoglobulin IGHV, IGHD and IGHJ genes in wild-derived and classical inbred mouse strains

“…It is also possible that the IGH loci of these strains include haplotype blocks derived from other lineages of the house mouse, or even from other Mus species such as M. spretus. Other subspecies of M. m. musculus probably exist, and a number have been proposed, such as M. m. bactrianus and M. m. gentilulus 41,42,43 .…”

Tracking the Near Eastern origins and European dispersal of the western house mouse

“…Despite being less variable than the more documented mitochondrial D-loop region, the cytochrome b gene allows the design of PCR primers that enable the amplification of very short fragments (the hypervariable region of the control region spans more than 300 bp in mice which prevents such design 48 ). Furthermore, Suzuki et al 97,98 have shown that the overall phylogenetic signal is congruent between the mitochondrial D-loop and the cytochrome b gene, with the same five main haplogroups being recognized within M. musculus. We designed the qPCR primers based on formerly published material for the cytochrome b gene from both house mouse and wild mice species 97 .…”