Comparative analysis (Hippotragini versus Caprini, Bovidae) of X-chromosome's constitutive heterochromatin by in situ restriction endonuclease digestion: X-chromosome constitutive heterochromatin evolution.
The Bovidae X-chromosome shows a considerable variation, in contrast to the preservative autosomal conservatism. The X-chromosome variation is mostly a consequence of the constitutive heterochromatin (CH) variation; in what respect to its amount and position. This is especially common among the non-Bovinae subfamilies and tribes. In order to characterize the X-chromosome CH in non-Bovinae species--Hippotragini and Caprini tribes--we have used restriction endonuclease digestion on fixed chromosomes and sequential C-banding. With these techniques we were able to distinguish between the two X-chromosome types (Hippotragini and Caprini) CH, in what respect to its position and molecular nature. Moreover, we define at least, six subclasses of CH in both X-chromosome types analyzed. Evolutionary considerations were draw based on the results obtained. The technology used here for the analysis of the Bovidae X-chromosome CH showed to be more evolutionary informative than the classical approaches.
Chaves
Raquel
R
Department of Genetics and Biotechnology, Centre of Genetics and Biotechnology/ICETA-UTAD, University of Trás-os-Montes and Alto Douro, P-5000-911 Vila Real, Portugal. rchaves@utad.pt
Santos
Sara
S
Guedes-Pinto
Henrique
H
D000818:Animals; D000866:Antelopes / Q000235:genetics*; D002871:Chromosome Banding; D019143:Evolution, Molecular; D014644:Genetic Variation; D006570:Heterochromatin / Q000235:genetics*; D007621:Karyotyping; D015183:Restriction Mapping; D034561:Sheep, Domestic / Q000235:genetics*; D014960:X Chromosome / Q000235:genetics*
D006570:Heterochromatin