PROJECT SUMMARY Zebrafish is a premiere organism to study vertebrate development, physiology, behavior, genetics, and disease. Powerful techniques allow efficient generation and recovery of zebrafish mutations affecting genes that regulate developmental patterning, organogenesis, physiology and behavior. Recent advances make it easy to study gene function in transgenic zebrafish and with antisense oligonucleotides. The functions of many, if not most of these genes are conserved among vertebrate groups. Thus, analysis of zebrafish mutations provides insights into gene function in other vertebrates, including humans. The Zebrafish International Resource Center (ZIRC) has been established as a repository that provides genetically modified animals, materials, and services to the research community. The parent grant provides funding 1) to serve as a central repository for zebrafish genetic stocks and research materials, 2) to provide pathology services and consultations, and 3) to develop a platform, based on a panel of PCR assays, to screen for the most prevalent pathogens of laboratory zebrafish. These materials, services, and information will be made widely available to the research community. Since its inception, ZIRC expends considerable time and resources on the facility's biosecurity when importing fish. We also maintain an extensive system to monitor the health of our stocks to limit the spread of two of the most common pathogens, Pseudoloma neurophilia and Mycobacterium chelonae. The requested supplemental funds will be used to alter and renovate the facility so that we can eliminate P. neurophilia infections in our wild-type stocks. We will alter the food preparation room and parts of the main fish facility, and we will purchase water filtration, fish housing, food room, and PCR diagnostic equipment. The equipment and space alterations will support screening for, rearing, and ultimately maintaining stocks that are free of P. neurophilia and have significantly lower prevalence of M. chelonae.