title: Evolution of genome organizations of squirrels (Sciuridae) revealed by cross-species chromosome painting.
abstract: With complete sets of chromosome-specific painting probes derived from flow-sorted chromosomes of human and grey squirrel (Sciurus carolinensis), the whole genome homologies between human and representatives of tree squirrels (Sciurus carolinensis, Callosciurus erythraeus), flying squirrels (Petaurista albiventer) and chipmunks (Tamias sibiricus) have been defined by cross-species chromosome painting. The results show that, unlike the highly rearranged karyotypes of mouse and rat, the karyotypes of squirrels are highly conserved. Two methods have been used to reconstruct the genome phylogeny of squirrels with the laboratory rabbit (Oryctolagus cuniculus) as the out-group: (1) phylogenetic analysis by parsimony using chromosomal characters identified by comparative cytogenetic approaches; (2) mapping the genome rearrangements onto recently published sequence-based molecular trees. Our chromosome painting results, in combination with molecular data, show that flying squirrels are phylogenetically close to New World tree squirrels. Chromosome painting and G-banding comparisons place chipmunks (Tamias sibiricus ), with a derived karyotype, outside the clade comprising tree and flying squirrels. The superorder Glires (orde Rodentia + order Lagomorpha) is firmly supported by two conserved syntenic associations between human chromosomes 1 and 10p homologues, and between 9 and 11 homologues.
authors.affiliation: Key Laboratory of Cellular & Molecular Evolution, Kunming Institute of Zoology, The Chinese Academy of Sciences, Kunming, Yunnan, People's Republic of China.
authors.forename: Tangliang
authors.initials: T
authors.lastname: Li
authors.forename: Patricia C M
authors.initials: PC
authors.lastname: O'Brien
authors.forename: Larisa
authors.initials: L
authors.lastname: Biltueva
authors.forename: Beiyuan
authors.initials: B
authors.lastname: Fu
authors.forename: Jinhuan
authors.initials: J
authors.lastname: Wang
authors.forename: Wenhui
authors.initials: W
authors.lastname: Nie
authors.forename: Malcolm A
authors.initials: MA
authors.lastname: Ferguson-Smith
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Graphodatsky
authors.forename: Fengtang
authors.initials: F
authors.lastname: Yang
mesh_terms: D000818:Animals; D005075:Biological Evolution; D002871:Chromosome Banding; D020223:Chromosome Painting; D002875:Chromosomes / Q000235:genetics*; D016678:Genome; D007621:Karyotyping; D051379:Mice; D010802:Phylogeny; D011817:Rabbits; D051381:Rats; D012589:Sciuridae / Q000235:genetics*