|Fahrenkrug, Scott - FORMER ARS EMPLOYEE|
|Alexander, Leeson - FORMER ARS EMPLOYEE|
Submitted to: Animal Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 15, 2001
Publication Date: June 1, 2002
Citation: Mccoard, S.A., Fahrenkrug, S.C., Alexander, L.J., Freking, B.A., Rohrer, G.A., Wise, T.H., Ford, J.J. 2002. An integrated comparative map of the porcine X chromosome. Animal Genetics. 33(3):178-185. Interpretive Summary: A detailed pig genomic map based on gene expression (EST) rather than microsatellites is required to take maximal advantage of human-pig comparative mapping strategies. The objective of the current study was to develop an integrated map of the porcine X chromosome that included both EST-associated markers and microsatellites. Positioning of 24 EST's on both genetic and physical maps produced an integrated comparative map of the porcine X chromosome that supports a very high degree of homology with the human X chromosome. This integrated map will be valuable to scientists for selection of candidate genes with porcine QTL's that map to the X chromosome.
Technical Abstract: Porcine Chromosome X (SSCX) harbors quantitative trait loci (QTL) responsible for testicular size and follicle-stimulating hormone (FSH) levels. In order to take maximal advantage of human-pig comparative mapping strategies for positional candidate gene cloning, a detailed pig comparative map employing expressed sequence tag (EST)-associated markers is required. Therefore, the objective of this study was to develop an integrated map of SSCX using both microsatellite and EST-associated markers. We sought to map porcine ESTs predicted by BLASTN analysis to represent orthologues of human genes resident on X chromosome. A physical map of SSCX was constructed using the T43 (3000 rads, 55 markers) and ImpRH (7000 rads, 31 markers) radiation hybrid (RH) panel mapping resources that differ in their resolution and public availability. These markers included 33 microsatellite and 22 EST-associated markers. In addition, 7 EST-associated SNP-based markers were developed and used for genetic mapping in the MARC reference family. Positioning of 24 ESTs on both genetic and physical maps translated to an integrated comparative map of the porcine genome that supports a striking conservation of synteny and no detected perturbations in gene order between SSCX and human Chromosome X. This integrated map will be valuable for selection of candidate genes for pig QTL mapped to SSCX.