A genetic linkage map and comparative mapping of the prairie vole (Microtus ochrogaster) genome

Here we report the construction of a genome-wide linkage map of the prairie vole. The linkage map consists of 406 markers that are spaced on average every 7 Mb and span an estimated ~90% of the genome. The sex average length of the linkage map is 1707 cM, which, like other Muroid rodent linkage maps, is on the lower end of the length distribution of linkage maps reported to date for placental mammals. Linkage groups were assigned to 19 out of the 26 prairie vole autosomes as well as the X chromosome. Comparative analyses of the prairie vole linkage map based on the location of 387 Type I markers identified 61 large blocks of synteny with the mouse genome. In addition, the results of the comparative analyses revealed a potential elevated rate of inversions in the prairie vole lineage compared to the laboratory mouse and rat.A genetic linkage map of the prairie vole has been constructed and represents the fourth genome-wide high-resolution linkage map reported for Muroid rodents and the first for a member of the Arvicolinae sub-family. This resource will advance studies designed to dissect the genetic basis of a variety of social behaviors and other traits in the prairie vole as well as our understanding of genome evolution in the genus Microtus.Genomes evolve by a number of molecular mechanisms including chromosomal rearrangements [1]. The genomes of rodents, in particular Muroid rodents (super-family: Muroidea) have been shown to have elevated rates of chromosomal rearrangements compared to most other placental mammals (e.g. [2]). Though the genome sequence of just two Muroid rodents, the laboratory mouse (Mus musculus) and rat (Rattus norvegicus), are currently available [3,4], interspecies comparisons based on cross-species comparative chromosome painting has provided a low-resolution view of the similarities and differences in genome organization in a number of species within this super-family (e.g. [5]).The genus Microtus is comprised of 62 species of voles and