Submitted to: Cytogenetics and Cell Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 18, 1998
Publication Date: N/A
Interpretive Summary: Livestock genome maps lack the resolution necessary for identifying the genes which underlie traits of economic importance. During our study to identify the gene resonsible for muscular hypertrophy (mh) or "double muscling" in cattle, we applied human comparative mapping information to improve the bovid physical map by identifying regions of genomic conservation between cattle, sheep and humans. Large genomic clones containing bovine orthologues of five genes located on the long arm of human Chr 2 (HSA2q) were physically mapped. Our results increased the resolution of the physical and comparative maps for sheep and cattle. Overall, this data reveals that complex rearrangements of gene order between bovid and human Chr2 provide an example of the potential difficulty researchers will encounter when applying comparative mapping information to identify genes associated with quantitative trait loci (QTL).
The cytogenetic locations of Protein C (PROC), Transition Protein 1 (TNP1), Intestinal Alkaline Phosphatase (ALPI), Engrailed (EN1) and human proto-interleukin beta (IL1B) genes have been compared between cattle and sheep. Bovine YAC and cosmid clones were used as FISH probes to determine the order (centromere-telomers orientation) of four of these genes on sheep chromosomes 2 and chromosome 3p. In cattle EN1 and IL1B were assigned to bovine chromosomes 2 and 11, respectively. The alignment between ovine, bovine and human physical maps using this data show that segments of conserved synteny and chromosomal rearrangements detected between cattle and human are aslo found in sheep, where the cattle order is conserved.