Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: June 10, 1996
Publication Date: N/A
Cattle (N=30) and sheep (N=27) have similar karyotypes with sheep having three metacentric chromosomes. Each metacentric chromosome represents the fusion of two bovine chromosomes. With the development of relatively high resolution bovine and ovine linkage maps, genomic conservation between the two Bovidae species can be evaluated using common markers derived from both species. Sixty six percent (348/500) of the microsatellite markers found on the current sheep map are also on the USDA-ARS cattle map. The number of common markers per bovine linkage group ranges from 5 to 21 with 26 of the markers originating from sheep and the remaining 322 derived from bovine sequences. The common markers span 2866 centimorgens (cM, sex-averaged) in sheep and 2817 cM in cattle or approximately 95% of each genome. Marker order within a linkage group was consistent between the two species with limited exceptions. The previously reported translocation of the telomeric end of BTA9 to BTA14 in sheep (OOV9) is represented by a 15 cM region containing 5 common markers. The other exceptions involved 5 independent markers (1.5% of 348 common markers) from different linkage groups that did not map to the expected homologue linkage group. The high degree of genomic conservation between sheep and cattle will allow us to simultaneously use conserved linkage and physical mapping information while searching for quantitative trait loci in both species.