Submitted to: Genome Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 25, 1996
Publication Date: N/A
Interpretive Summary: A prerequisite to fine mapping and marker assisted selection (MAS) of quantitative trait loci (QTLs) is the development of a genetic map with a high density of informative markers. Previous maps of bovine chromosome 1 (BTA1) contained less than seventeen informative DNA markers each, and thereby, lacked sufficient DNA marker density and genome coverage to be used for fine mapping or MAS. We used a chromosome specific library to systematically increase DNA marker density for BTA1. Forty-four new DNA markers were identified. Genotypic data from these 44 markers and 24 previously unlinked markers were generated from the MARC families and integrated into the existing USDA/MARC BTA1 linkage group. The number of linked microsatellite markers was increased from 16 to 84. This BTA1 linkage map spans 153 cM (average interval of 1.9 cM). In addition, the linkage map was integrated with the physical map to define the extent of coverage. The more than four-fold improvement in informative marker density of BTA1 provides a genetic map that will enhance fine mapping and MAS of QTLs and QTL analysis within and between breeds of cattle.
Genetic resolution of bovine chromosome 1 (BTA1) linkage group was significantly increased by screening for microsatellite (ms) clones in a microdissected library constructed from a bovine cell line carrying a t(1;29) translocation. Eighty-five percent of the ms (46/54) identified were informative in the USDA/MARC mapping population, and 96% of these ms (44/46) linked to BTA1 (LOD>3.0). When merged with 40 existing BTA1 markers the genetic map spanned 153.8 cM (sex avg. interval 1.9 cM). Two cosmids probes physically assigned by fluorescence in situ hybridization defined the extent of coverage of the BTA1 linkage group. The greater than four-fold improvement in informative marker density of BTA1 provides a genetic map that enhances quantitative trait loci (QTL) mapping and implementation of marker assisted selection (MAS).