PAG-V: P318 - CHROMOSOME EVOLUTION IN EQUIDS: ZOO-FISH STUDIES OF THE HORSE, DONKEY AND HARTMANN'S ZEBRA USING HUMAN, WHOLE CHROMOSOME PAINTS

Plant & Animal Genome V Conference

Town & Country Hotel, San Diego, CA, January 12-16, 1997.

P318

CHROMOSOME EVOLUTION IN EQUIDS: ZOO-FISH STUDIES OF THE HORSE, DONKEY AND HARTMANN'S ZEBRA USING HUMAN, WHOLE CHROMOSOME PAINTS

LEAR, TERI L., Ernest Bailey
MH Gluck Equine Research Center, University of Kentucky, Lexington, KY 40546

Chromosome painting studies have demonstrated that large blocks of chromosomal DNA have been conserved between species during evolution. Equids are thought to have undergone rapid chromosomal evolution during their speciation, about 5 million years before present, as demonstrated by differences in chromosome number and banding patterns despite their ability to produce viable, albeit sterile, hybrids. Here we report the hybridization of human, whole chromosome paints for HSA 4, 8, 9, 16 and 21 by Zoo-FISH studies on horse, donkey and/or Hartmann's zebra chromosomes. Differences were apparent between species indicating that complex chromosomal rearrangements have occurred. HSA 4 hybridized to horse 2q and 3q and to a single metacentric chromosome in both the donkey and the zebra. HSA 8 weakly hybridized along the length of horse chromosome 9 and to narrow pericentromeric regions on two metacentric zebra chromosomes. HSA 9 hybridized to horse chromosomes 23 and 25, to the p arm of a metacentric chromosome and to an acrocentric chromosome in the donkey, and to the pericentromeric regions of two metacentric zebra chromosomes. HSA 16 identified segments on horse chromosomes 3p and 13q, two acrocentric chromosomes in the donkey and two small regions on the p arms of two metacentric zebra chromosomes. HSA 21 hybridized to horse chromosome 28 and to a narrow distal region on the q arm of a metacentric zebra chromosome. From this preliminary data, these studies could provide data clarifying the types of complex rearrangements which have occurred during the rapid chromosomal evolution of the Equidae.