Recent fusion events during evolution of pig chromosomes 3 and 6 identified by comparison with the babirusa karyotype.
The chromosomes of the babirusa, a species considered to have diverged from an ancestor of the pig during the Miocene epoch, about 12-26 million years ago, were studied to determine the sites of recent rearrangements during evolution of the domestic pig. It is shown that there is a pericentric inversion of the entire short arm on pig chromosome 1, compared to its counterpart in the babirusa (chromosome 15). We also present evidence suggesting that pig chromosome 3 was derived by a telomere-centromere fusion of two ancestral chromosomes homoelogous to babirusa chromosomes 12 and 17. Likewise, we conclude that pig chromosome 6 was most likely derived by a telomere-telomere fusion of ancestral chromosomes homoelogous to babirusa chromosomes 6 and 14. The detection of interstitial hybridization signals from presumptive subteloemeric repeats in the same chromosome region as the evolutionary fusion points on pig chromosomes 3 and 6 indicates that the fusion sites may still contain elements that are otherwise restricted to the telomere regions of pig chromosomes.
Thomsen
P D
PD
Department of Anatomy and Physiology, Royal Veterinary and Agricultural University, Copenhagen, Denmark. Preben.D.Thomsen@iaf.kvl.dk
Høyheim
B
B
Christensen
K
K
D000818:Animals; D002478:Cells, Cultured; D002875:Chromosomes; D003001:Cloning, Molecular; D019143:Evolution, Molecular; D007621:Karyotyping; D008297:Male; D013552:Swine / Q000145:classification / Q000235:genetics*