EUCOMM Conditional Vector and ES Cell Clone Collection Acquisition and Procurement Plan by the MMRRC at UC Davis ABSTRACT The Mutant Mouse Resource and Research Center at the University of California, Davis (MMRRC) is pleased to submit this administrative supplement for support during the current grant year (ending January 31, 2025) in response to EMAIL . This application proposes the procurement and acquisition of data, molecular vectors, and ES cell clones for 2,751 genes targeted as knockout-first alleles produced by the EUCOMM project at Helmholtz Zentrum Munich for the original EUCOMM Program. These genes are unique to the set of conditionally-targeted genes produced by KOMP2 as part of the International Mouse Phenotyping Consortium (IMPC), are not already in the MMRRC, and are not readily available and accessible by the US research community. Further, because the US research community continues to actively express interest in mouse models expressing conditional alleles for use in their NIH-funded R01 research and other scientific projects, ensuring availability and access to the EUCOMM collection is paramount. However, support for the maintenance and preservation of this collection is being discontinued which puts their future availability for research in jeopardy despite their continued use and interest. The cost to transfer ownership and stewardship of this resource is a very small fraction (~3%) of what it would cost to recreate it using CRISPR-mediated gene-targeting in ES cells. Once fully imported and incorporated into the MMRRC, the collection would be available for distribution to the biomedical research community, especially NIH funded investigators who continue to express interest in conditional, lacZ tagged alleles. As a result of the activities funded by this administrative supplement, procurement and acquisition of the EUCOMM conditional alleles will exert a sustained, powerful influence on research field(s) using conditional mouse models and the overall ORIP mission to support a variety of resource and research centers that develop animal models of human biology and disease for biomedical researchers not only in the US, but around the world. The costs to execute this project are beyond the available support provided by the parent MMRRC grant to UC Davis. If awarded, funds will be used to complete this project during the current grant year (ending January 31, 2025). A budget of $534,139 total direct costs ($681,529 total costs) is requested to fund activities that all fall within the scope of the parent award.