Submitted to: Animal Genetics
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/25/2001
Publication Date: 8/1/2001
Citation: CAMPBELL, E.M., FAHRENKRUG, S.C., VALLET, J.L., SMITH, T.P., ROHRER, G.A. SHORT COMMUNICATION: AN UPDATED LINKAGE AND COMPARATIVE MAP OF PORCINE CHROMOSOME 18. ANIMAL GENETICS. 2001. v. 32. p. 375-379. Interpretive Summary: Chromosome 18 has the fewest genetic markers of any swine chromosome. Increasing the marker density on this chromosome would facilitate selection of useful markers for identifying economically important trait genes. A targeted marker development approach was implemented which utilized the human gene map. Genetic markers were developed which resided near genes expected to map to pig chromosome 18 based on the current human-pig comparative map. These markers were then mapped across the US-MARC swine reference population. Seventeen new genetic markers were developed with fifteen mapping to pig chromosome 18. These results have more than doubled the number of markers on this chromosome and have determined the location of seven genes in the pig genome. The gene assignments have increased the resolution of the human-pig comparative map and detected a previously unknown rearrangement between the human and porcine genomes.
Technical Abstract: Swine chromosome 18 (SSC18) has the poorest marker density in the USDA-MARC porcine linkage map. In order to increase the marker density, seven genes from human chromosome 7 (HSA7) expected to map to SSC18 were selected for marker development. The genes selected were: growth hormone releasing hormone receptor (GHRHR), GLI-Kruppel family member (GLI3), leptin (LEP), capping protein muscle Z-line alpha 2 subunit (CAPZA2), beta A inhibin (INHBA) and T-cell receptor beta (TCRB) and gamma (TCRG). Large-insert clones (YACs, BACs and cosmids) that contained these genes, as well as two previously mapped microsatellite markers (SW1808 and SW1984), were identified and screened for microsatellites. Novel microsatellite markers were developed from these clones and mapped. Selected clones were also physically assigned by fluorescence in situ hybridization (FISH). Fifteen new microsatellite markers were included on the SSC18 linkage map and one gene (TCRG) mapped to SSC9. This research has more than doubled the marker density on SSC18 and helped define conserved syntenic segments between SSC18 and HSA7.