title: Reorganization of the X chromosome in voles of the genus Microtus.
abstract: Comparative chromosomal analysis is a powerful tool in the investigation of the mechanisms of chromosomal evolution. The accuracy of the analysis depends on the availability of region-specific markers to follow the fate of the particular chromosomal region through the evolution of species. We have assigned 12 unique sequences to the euchromatic part of the vole X chromosome, which serve as reliable markers of chromosomal segments. Together with region-specific libraries and GTG banding, these markers allow us to delineate the homologous regions of the X chromosomes in five species of the genus Microtus. We found that X chromosomes of these species differ by numerous rearrangements and all rearrangements are clustered at specific breakpoints. Moreover, these breakpoints were found to colocalise with repetitive and/or duplicated DNA sequences. We suggest that clusters of repeated and/or duplicated DNA sequences have played a crucial role in the formation of rearrangement hot spots during evolution of the X chromosome in the subgenus Microtus.
authors.affiliation: Institute of Cytology and Genetics, Russian Academy of Sciences, Siberian Department, Novosibirsk, Russia.
authors.forename: N B
authors.initials: NB
authors.lastname: Rubtsov
authors.forename: N V
authors.initials: NV
authors.lastname: Rubtsova
authors.forename: O V
authors.initials: OV
authors.lastname: Anopriyenko
authors.forename: T V
authors.initials: TV
authors.lastname: Karamysheva
authors.forename: A I
authors.initials: AI
authors.lastname: Shevchenko
authors.forename: N A
authors.initials: NA
authors.lastname: Mazurok
authors.forename: T B
authors.initials: TB
authors.lastname: Nesterova
authors.forename: S M
authors.initials: SM
authors.lastname: Zakian
mesh_terms: D000818:Animals; D003411:Arvicolinae / Q000235:genetics*; D002871:Chromosome Banding; D002874:Chromosome Mapping; D015342:DNA Probes; D019143:Evolution, Molecular; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D013045:Species Specificity; D014960:X Chromosome / Q000235:genetics*
chemical_list: D015342:DNA Probes