Technical Abstract: Recent advances in molecular genetics will contribute to conservation of genetic resources. Linkage maps have been developed for several livestock species, including cattle and swine. These maps allow the identification of chromosomal regions associated with production traits. This information is used in the search for genes responsible for the expression of traits. Potential candidate genes can be selected based on information from comparative maps. A wealth of information will be available from the human and mouse genome projects to identify genes influencing economically important traits. New technology will allow the search for differences in genes sequences on nonelectrophoresis-based chips, allowing a search of thousands of genes at a time. Using this technology, it will be possible to search for chromosomal regions and differences in gene sequences that have given local genetic resources their identity. It will be necessary to omaintain, study and classify these resources on a molecular basis to accomplish the goal of conservation program.