R. Chaves et al., The species and chromosomal distribution of the centromeric a-satellite I sequence from sheep in the tribe Caprini and other Bovidae, CYTOG C GEN, 91(1-4), 2000, pp. 62-66
The evolution of chromosomes in species in the family Bovidae includes fusi
on and fission of chromosome arms (giving different numbers of acrocentric
and metacentric chromosomes with a relatively conserved total number of arm
s! and evolution in both DNA sequence and copy number of the pericentromeri
c alpha -satellite I repetitive DNA sequence. Here, a probe representing th
e sheep alpha -satellite I sequence was isolated and hybridized to genomic
DNA. digests and metaphase chromosomes from various Bovidae species. The pr
obe was highly homologous to the centromeric sequence in all species in the
tribe Caprini, including sheep (Ovis aries), goat (Capra hircus and the ao
udad or Barbary sheep (Amnotragus lervia). but showed no detectable hybridi
zation to the alpha -satellite I sequence present in the tribe Bovini and a
t most very weak to species in the tribes Hippotragini, Alcelaphini or Aepy
cerotini. The sex chromosomes of sheep, goat and aoudad did not contain det
ectable alpha -satellite I sequence, in sheep, one of the three metacentric
autosomal chromosomes does not carry the sequence, while in aoudad, it is
essentially absent in three large autosomal pairs as well as the large meta
centric chromosome pair. The satellite probes can be used as robust chromos
ome and karyotype markers of evolution among tribes and increase the resolu
tion of the evolutionary tree at the base of the Artiodactyla. Copyright (C
) 2001 S. Karger AG, Basel.