Comparative FISH mapping of bovid X chromosomes reveals homologies and divergences between the subfamilies bovinae and caprinae.
Comparative FISH mapping of river buffalo (Bubalus bubalis, BBU), sheep (Ovis aries, OAR), and cattle (Bos taurus, BTA) X chromosomes revealed homologies and divergences between the X chromosomes in the subfamilies Bovinae and Caprinae. Twenty-four and 17 loci were assigned for the first time to BBU X and OAR X, respectively, noticeably extending the physical map in these two species. Seventeen loci (four of which for the first time) were also FISH mapped to BTA X and used for comparative mapping studies on the three species, which show three morphologically different X chromosomes: an acrocentric (BBU X), an acrocentric with distinct short arms (OAR X), and a submetacentric (BTA X). The same order of loci were found on BTA X and BBU X, suggesting that a centromere transposition, with loss (cattle) or acquisition (river buffalo) of constitutive heterochromatin, differentiated the X chromosomes of these two bovids. Comparison of bovine (cattle and river buffalo) and caprine (sheep) X chromosomes revealed at least five common chromosome segments, suggesting that multiple transpositions, with retention or loss of constitutive heterochromatin, had occurred during their karyotypic evolution.
Iannuzzi
L
L
National Research Council, IABBAM, Naples, Italy.
Di Meo
G P
GP
Perucatti
A
A
Incarnato
D
D
Schibler
L
L
Cribiu
E P
EP
D000818:Animals; D002020:Buffaloes; D002417:Cattle; D002871:Chromosome Banding; D002876:Chromosomes, Bacterial / Q000235:genetics; D004247:DNA / Q000235:genetics; D014644:Genetic Variation; D006041:Goats; D017404:In Situ Hybridization, Fluorescence; D020161:Physical Chromosome Mapping; D012756:Sheep; D013045:Species Specificity; D014960:X Chromosome / Q000235:genetics*
D004247:DNA