A 2ND-GENERATION LINKAGE MAP OF THE BOVINE GENOME

We report a bovine linkage map constructed with 1236 polymorphic DNA m arkers and 14 erythrocyte antigens and serum proteins. The 2990-cM map consists of a sex-specific, X chromosome linkage group and 29 sex-ave raged, autosomal linkage groups with an average interval size of 2.5 c M. The map contains 627 new markers and 623 previously linked markers, providing a basis for integrating the four published bovine maps. Ori entation and chromosomal assignment of all the linkage groups, except BTA20 and BTA22, was provided by 88 markers that were assigned previou sly to chromosomes. This map provides sufficient marker density for ge nomic scans of populations segregating quantitative trait loci (QTL) a nd subsequent implementation of marker-assisted selection (MAS) mating schemes.