Mapping the bovine genome: methodological aspects and strategy*

Summary The mapping of genes that control traits of economic importance will ultimately lead to the unravelling of the molecular basis of genetic variation. The main prerequisite for mapping of the unknown genes is a sufficient number of highly polymorphic marker loci which are evenly distributed along the chromosomes. The establishment of such a marker map in cattle and other species is based on methods used in human gene mapping. Comparative mapping facilitates saturation of the chromosomes with markers by utilizing the high degree of conservation of synteny among mammalian species. Comparative mapping will also allow access to the detailed mapping data and to extensive sequence information expected from the human genome initiative.