Submitted to: Colloquium on Domestic Animal Cytogenetics and Gene Mapping
Publication Type: Proceedings
Publication Acceptance Date: 5/30/1997
Publication Date: N/A
Technical Abstract: The usefulness of genetic maps is a function of genomic coverage and integration of linkage and physical cytogenetic maps. The search for loci associated with complex traits (QTLs) in livestock species requires that genetic maps be constructed from a significant number of highly polymorphic markers evenly distributed over the total genome length. The goal of this work was to physically assign polymorphic markers located at the telomeric and centromeric ends of bovine linkage groups for integrating the physical and linkage maps and estimating the physical coverage. We report such integration and estimates of physical coverage for nine bovine linkage groups using cosmid clones for physical assignment by FISH. Microsatellite markers from each end of the nine linkage groups were used to identify cosmid clones by a PCR iterative screening method. Results indicate that the linkage groups cover 72% (BTA15) to 98% (BTA22) of the length on these chromosomes. The need to develop additional markers for improving coverage is greatest for BTA15. The physical map of BTA1, 3, 16, 17, 20, 22, and 28 appears to adequately cover the respective chromosome whereas the map of BTA29 suggests an inflation of the linkage group near the telomeric end. Integration of both maps and the physical coverage estimates determine how well the current linkage groups cover the chromosomes and are useful to detect map inflated regions.