ABSTRACT Mice and humans share approximately 20,000 genes. To date, little data exists for more than a quarter of these genes and nearly one third have no functional annotation. Because of the high degree of similarity between the mouse and human gene set, genetic data generated in mice can often be extrapolated to human gene function. Mouse models of genes with common functionality between mice and humans can lead to new models of disease, which are useful for drug screening, preclinical studies, and deeper understanding of biological and disease mechanism. The goal of the Knockout Mouse Phenotyping Program (KOMP2) is to generate lines of mice that carry knockouts (KOs) for a genome-wide collection of mouse genes and subject the mice to broad based phenotyping. JAX KOMP2 phase 3 proposes to use cutting-edge and cost-effective Cas9 RNA-guided nuclease (Cas9 RGN, also called CRISPR/Cas9) technology to generate, breed, cryopreserve and phenotype 600 lines of mice during the project period. Continued effort will be made to improve the Cas9 RGN technology so as to reduce costs, increase targeting efficiency, and create more complex mutant alleles. Genes will be selected in coordination with our KOMP2 and IMPC partners and will focus on those that; have human orthologs, have not been previously knocked out, have no or poor annotation, have significant community demand and integrate with other NIH-support programs, or are predicted to function in select pathways. To guarantee ready access to the community, we will ship mice to outside investigators while they are alive on the shelf and deposit the lines into the Mouse Mutant Regional Resource Center (MMRRC) repositories for future use. Broad based phenotyping on young adult mice up to 17 weeks of age will be performed on all 600 lines of mice using International Mouse Phenotyping Consortium (IMPC)-required and JAX-specific protocols. We will assess body weight and composition, and behavior, cardiovascular, metabolic, ocular and physiological parameters. Based on data generated from the current phase of KOMP2, we expect about 30% of lines to be non-viable. We will characterize the non-viable mutants using high-throughput imaging modalities at three embryonic time points. Based on previous data we also expect approximately 7% of the lines to be infertile. Direct fertility testing to assess the fertility of each sex will be performed on all lines that fail to generate offspring from homozygous by homozygous matings. All data generated from embryonic and adult mice will be rapidly deposited into the Data Coordination Center (DCC) that supports KOMP2 and the IMPC. Lastly, JAX will work collaboratively with the KOMP2 Regional Network and with member organizations of the IMPC to share protocols, innovation, and new technology and to broadly and openly disseminate our findings to the international community through publication, presentations at meetings, web activities, and social media.

RELEVANCE TO PUBLIC HEALTH The Knockout Mouse Phenotyping Program (KOMP2) seeks to create an encyclopedia of gene function for the ~20,000 genes in the mouse and to ultimately create a resource for understanding gene function in humans. The Jackson Laboratory (JAX) KOMP2 Phase 3 Center will contribute to this goal by efficiently generating and characterizing knockout lines and sharing functional data for 600 mouse genes. The JAX team will enhance the value of these data by linking them with current genetic and biological knowledge, enabling the scientific community to discover the roles of these genes in human health and disease.