Submitted to: Swine Chromosome 7 Workshop
Publication Type: Proceedings
Publication Acceptance Date: September 15, 1995
Publication Date: N/A
Technical Abstract: Although remarkable progress has recently been made in genetic linkage mapping in cattle, swine and sheep (Barendse et al. 1994; Bishop et al. 1994; Ellegren et al. 1994; Rohrer et al. 1994; Archibald et al. 1995; Crawford et al. 1995), economic reality suggests that the current mapping effort within each species will not link more than 25-30% of the ~6000 markers currently linked on either the human or mouse maps in the near future, if at all. Relatively few new ms markers are being developed from small insert libraries of randomly cloned cattle, swine or sheep DNA. Addition of informative coding loci to any of the species maps is slowed by low marker heterozygosity in mapping families and lack of an integrated, concerted effort. In the near term, construction of consensus linkage maps should improve resolution within individual linkage groups. However, as only indirect estimates of genomic size are available for any of the major livestock species and the informative telomeric and centromeric markers necessary for a more rigorous analysis are not yet available, consensus maps may not immediately improve overall genomic coverage (Beattie, 1994). Integration of informative physically anchored loci into a comprehensive linkage map significantly improves estimates of chromosomal coverage and resolution by improving linkage group orientation, verifying sequential order, and detecting differential recombination rates within the genome. Unfortunately, marker deficient regions (gaps) in the current linkage maps for cattle, swine and sheep and paucity of polymorphic loci physically anchored to individual chromosomes have severely limited development of high resolution linkage maps for these species. A consensus strategy(s) to overcome these limitations.