Genome-wide comparative chromosome map between human and the Forrest's pika (Ochotona forresti) established by cross-species chromosome painting: further support for the Glires hypothesis.

Comparative genomic data for ochotonids (pikas) are important for understanding the karyotype evolution of lagomorphs. Here, we have established the first genome-wide chromosomal homologies between human and the Forrest's pika (Ochotona forresti, 2n = 54) by cross-species chromosome painting. Integration of our map with the published comparative chromosome map between human and rabbit has enabled the establishment of an indirect homology map between Forrest's pika and domestic rabbit (Oryctolagus cuniculus, 2n = 44), representing the 2 Lagomorpha families: Leporidae and Ochotonidae. Our results demonstrate that (1) most of the proposed ancestral eutherian syntenies or syntenic associations have been retained in the O. forresti genome; (2) the HSA1/10p association, one of the 2 signature rearrangements that were proposed to support the grouping of the orders Lagomorpha and Rodentia into a monophyletic clade called Glires, is also present in the O. forresti genome; and (3) Robertsonian translocations have contributed to the karyotype differences between O. forresti and O. cuniculus.