Genetically engineered rodents are essential for understanding gene function in the context of the whole animal. This is especially important for alcohol research as we ultimately seek to understand the role of individual candidate genes on endpoints that can only be studied at the organism level, e.g., alcohol drinking and alcohol-induced behavioral responses. To service the needs of the INIA-West for genetically engineered animals, this core will provide the following services to consortium investigators. Aim 1 services will provide consultation to investigators regarding model development and construct design. Aim 2 services all relate to gene targeted mouse production including production of targeting vectors, gene targeting in embryonic stem cells, production of chimerical mice, and breeding to establish mutant mouse lines. Transgenic mouse services are the focus of Aim 3. This aim includes transgene production, embryo microinjection, and identification of founder animals. Lastly, Aim 4 involves the application of recently developed zinc-finger nuclease technology to produce knockout rats. Zinc-finger nucleases will be purchased from a commercial vendor and this core will inject them into rat embryos and identify the gene targeted rats that result.