Plant & Animal Genome VI Conference

P68

CHARACTERIZATION OF TEN DINUCLEOTIDE MICROSATELLITE LOCI IN THE HORSE (Equus caballus)

Department of Morphology, Genetics and Aquatic Biology, Norwegian College of Veterinary Medicine, POBox 8146 Dep., N-0033 Oslo, Norway

Ten Equine dinucleotide microsatellite loci identified at the Norwegian College of Veterinary Medicine (NVH) were examined for polymorphism on a panel of 30-40 individuals from each of the breeds Norwegian Fjord horse, Norwegian Nordland horse, Norwegian trotter, Standardbred trotter and Thoroughbred. One locus seems to be X-chromosome linked, the nine other loci has unknown location on autosomal chromosomes. All loci proved to be polymorphic, showing between three and 13 alleles. Average level of expected heterozygosity (H_e) for the ten markers varied between 0.52 and 0.72. Heterozygosity within some loci varied considerably between breeds; locus NVHEQ54 showed a range in H_e from 0.03 in the Standardbred to 0.50 in the Fjord horse, and locus NVHEQ79 showed a range in H_e from 0.18 in the Thoroughbred to 0.77 in the Norwegian trotter. The results indicate that the majority of the loci show relative large level of variation with H_e as high as 0.80 for some loci in some of the examined breeds, which suggest that these markers could serve well in identity- and parentage testing, as well as being useful in the gene map work of the horse. The results also indicate that the relative small population of the Norwegian breeds of Nordland horse and Fjord horse do not experience particularly loss of genetic variation despite their restricted distribution.