Cytogenetic analyses of chromosomal rearrangements in Mus minutoides/musculoides from North-West Zambia through mapping of the telomeric sequence (TTAGGG)n and banding techniques.
Three specimens of M. minutoides/musculoides from Zambia were cytogenetically studied through G- and C-banding, DAPI staining and fluorescence in-situ hybridization (FISH) with a (TTAGGG)n telomeric sequence. Biarmed chromosomes were identified according to the current nomenclature as follows: Rb(2.7), Rb(3.12), Rb(4.5), Rb(6.8), Rb(9.16), and the sex chromosomes Rb(1.X), Rb(1.Y) and Rb(1.Xd), originated from the deleted X chromosome. One female showed the diploid number 2n = 24; in the two other individuals, the Rb(9.16) occurred in a heteromorphic condition, and, accordingly, the diploid number was 2n = 25. FISH showed the sites of telomeric sequences at telomeres of all the chromosomes, and in an interstitial position at the centromeres of all Robertsonian metacentrics, except one - the Rb(6.8), though the patterns of hybridization varied between chromosomes. Sex chromosome pairs, in the male and females, showed a similar C-banding pattern, but revealed clear differences after FISH. Traces of telomeric sequences were found dispersed in the whole-heterochromatic arm of the Rb(1.Xd). No visible bond between C-positive heterochromatin and telomeric sequences were detected in the other either bi- or uniarmed chromosomes, indicating that they may actually represent retained telomeres in the Robertsonian metacentrics.
Castiglia
Riccardo
R
Department of Animal and Human Biology, University of Rome La Sapienza, Italy. castiglia@uniroma1.it
Gornung
Ekaterina
E
Corti
Marco
M
D000818:Animals; D002869:Chromosome Aberrations; D002871:Chromosome Banding / Q000379:methods*; D015342:DNA Probes; D017404:In Situ Hybridization, Fluorescence; D007211:Indoles; D051379:Mice / Q000235:genetics*; D012730:Sex Chromosomes; D016615:Telomere / Q000235:genetics*; D015024:Zambia
D015342:DNA Probes; D007211:Indoles; C007293:DAPI