Mouse genetic models have been extensively utilized by Washington University musculoskeletal investigators and are central to research of musculoskeletal biology and medicine. Although there have been many successful research activities by individual investigators within the musculoskeletal research community, there has not been a mechanism in place to facilitate the production, acquisition and sharing of pertinent mouse genetic models among the investigators. There has also been a lack of training and education for non-expert users. Thus, to foster a more sufficient and synergistic research environment for musculoskeletal researchers at Washington University, the Mouse Genetic Models Core is dedicated to supporting production, preservation and sharing of genetically altered mice for Center investigators in a timely and reliable manner. Specifically, the Mouse Genetic Models Core is to achieve four specific goals. Aim1: Production of genetically modified mice. The mouse genome can be altered using two general approaches: (i) incorporation of synthetic genes via direct injection of DNA into single-celled embryos, or (ii) creation of targeted mutations that are induced in embryonic stem (ES) cells by homologous recombination and then incorporate into the germ line. For ES cell manipulation, we will take advantage of the existing ES core at Washington University. For microinjections of either correctly targeted ES cells or DNA constructs, we will utilize the existing Mouse Genetics Core. Aim2: Cryopreservation of transgenic mouse strains. This will also be performed at the existing Mouse Genetics Core. Aim3: Consultation and education. The Core Directors will advice investigators on mouse genetic strategies. Aim4: Maintain database of available murine models. This aim takes advantage of the existing expertise and reagents at Washington University to establish and publicize a campus-wide database for transgenic mouse strains relevant to musculoskeletal studies. Overall, the Mouse Genetic Models Core will maximize the benefit of existing mouse genetic resources through subsidized services to expedite musculoskeletal studies at Washington University.