Open AccessTracking Chromosome Evolution in Southern African Gerbils Using Flow-Sorted Chromosome Paints
Author(s) -
L.I. Knight,
Bee Ling Ng,
William Cheng,
Beiyuan Fu,
Fengtang Yang,
Ramugondo V. Rambau
Publication year - 2013
Publication title -
cytogenetic and genome research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.571
H-Index - 88
ISSN - 1424-8581
DOI - 10.1159/000350696
Subject(s) - biology , chromosome , gene flow , genetics , tracking (education) , evolutionary biology , gene , genetic variation , psychology , pedagogy
Desmodillus and Gerbilliscus (formerly Tatera) comprise a monophyletic group of gerbils (subfamily Gerbillinae) which last shared an ancestor approximately 8 million years ago; diploid chromosome number variation among the species ranges from 2n = 36 to 2n = 50. In an attempt to shed more light on chromosome evolution and speciation in these rodents, we compared the karyotypes of 7 species, representing 3 genera, based on homology data revealed by chromosome painting with probes derived from flow-sorted chromosomes of the hairy footed gerbil, Gerbillurus paeba (2n = 36). The fluorescent in situ hybridization data revealed remarkable genome conservation: these species share a high proportion of conserved chromosomes, and differences are due to 10 Robertsonian (Rb) rearrangements (3 autapomorphies, 3 synapomorphies and 4 hemiplasies/homoplasies). Our data suggest that chromosome evolution in Desmodillus occurred at a rate of ~1.25 rearrangements per million years (Myr), and that the rate among Gerbilliscus over a time period spanning 8 Myr is also ~1.25 rearrangements/Myr. The recently diverged Gerbillurus (G. tytonis and G. paeba) share an identical karyotype, while Gerbilliscus kempi, G. afra and G. leucogaster differ by 6 Rb rearrangements (a rate of ~1 rearrangement/Myr). Thus, our data suggests a very slow rate of chromosomal evolution in Southern African gerbils.