|Ponce De Leon, F|
Submitted to: Animal Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/15/2004
Publication Date: 9/18/2004
Citation: Mizoshita, K., Ihara, N., Carpio, C.M., Bennett, G.L., Ponce De Leon, F.A., Beattie, C.W., Sugimoto, Y. 2004. Chromosomal mapping of 65 microsatellites developed from microdissected BTA14 and BTA20 chromosome-specific genomic libraries. Animal Genetics 35:408-410. Interpretive Summary: The ability to find and develop genetic markers for specific cattle chromosomes can speed the search for the location of genetic differences in traits that are important for efficient production of safe and desirable beef. A laboratory technique was used to find genetic markers on cattle chromosomes 14 and 20. These markers were then genotyped in a pedigreed population of cattle. In total, the procedure resulted in 25 markers located on chromosome 14 and 32 on chromosome 20. This information adds additional tools that will be used by researchers trying to identify the genetic basis for economic differences in cattle.
Technical Abstract: BTA14 and BTA20 chromosome-specific genomic libraries were developed from a bovine-transformed fibroblast cell line containing the t(1;29) and t(20;14) translocations. Chromosomal inserts were prepared from scraped chromosomes from coverslips preparation, and ligated into vector. The resulting libraries were screened with 32P-end labelled (GT)15, (GC)15, (AT)15 and (AGC)10. Positive clones were sequenced. All sequences were queried against GenBank by BLAST. Polymerase chain reaction (PCR) primers were designed interactively. Oligonucleotide primer pairs for each locus were optimized for PCR amplification by testing over a range of annealing temperatures. Polymorphisms in each locus were identified by examining 28 parents of the USDA-MARC mapping population. The PCR product sizes were measured and analyzed for the USDA-MARC mapping population by genotyping software. Chromosomal assignments of microsatellite loci were based on sex-averaged two-point LOD scores >3.0. Sixty-five polymorphic microsatellite markers were developed from the two libraries. Of the 65 markers, 33 were from the BTA14 chromosome-specific library, and 25 were subsequently located to BTA14. The remaining eight microsatellite markers were located on chromosomes other than BTA14, indicating the complexity of the translocation and chromosome rearrangement in the bovine cell line. Thirty-two microsatellites were developed from the BTA20 chromosome-specific library, and all were located to BTA20. Previous reports have described the successful use of chromosome-specific libraries for developing microsatellite markers to increase marker density on specific chromosomes. These polymorphic microsatellites should accelerate fine mapping of quantitative trait loci located on these two chromosomes as well as positional cloning of their responsible genes.