Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: June 10, 1996
Publication Date: N/A
Technical Abstract: A prerequisite to identifying quantitative trait loci (QTLs) is the development of a genetic linkage map containing enough informative markers to maximize genome coverage. The resolution of any linkage maps depends upon the number of informative markers and the number of informative meioses per marker. Current genetic livestock maps contain enough informative markers to identify QTLs, but lack sufficient density to be used for either fine mapping of a QTL or marker assisted selection (MAS) within and between breeds. Chromosome specific microdissected libraries provide a source of DNA which can be screened for microsatellites (MS) to systematically increase marker density in a region specific manner. We have constructed such a library from chromosome 1 (BTA1). In the initial MS screen of our BTA1 library, approximately 6 x 104 small insert lambda plaques (1/4 chromosome equivalent) were screened with a radiolabeled (GT)11 probe. Fifty-three of the seventy-four clones sequenced yielded unique MS markers. Forty-six of the MS markers were informative. Linkage analysis of genotypic data generated from the MARC families showed 44 of these MS markers linked on BTA1 with a LOD (>3). The integration of these 44 MS markers into USDA/MARC's BTA1 linkage group increased the number of linked markers from 56 to 100 and spans 152 cM (sex ave. interval of 1.5 cM). The nearly two-fold improvement in informative marker density of BTA1 provides a genetic map which will enhance implementation of physical mapping or MAS.