The Peromyscus (Deer Mouse) Genetic Stock Center, established in 1985 as an outgrowth of a pre-existing research animal colony, contains 28 well-characterized mutant lines and several stocks of "wild-type" animals representing three species. Live and preserved animals, fresh tissues and other materials derived from Peromyscus are provided to the scientific community as a national resource. This project will allow expansion of the Center to include live stocks of three additional species as well as molecular materials of Peromyscus origin. The Center will be extended to include any genetic resources relating to Peromyscus, including purified nuclear and mitochondrial DNA, molecular probes, genomic and cDNA libraries, cell lines, skins of variant types, photographs, research and pedigree records and publication reprints, all of which will be available from this central source. The Center will also add at least six behavioral mutant lines, and will establish a backup colony at a remote site in case of a catastrophic disaster. Current services and activities of the Center, including distribution of live and preserved Peromyscus, publication of a newsletter, and service as a repository of historical materials, will continue.