NHGRI/DIR Embryonic Stem Cell and Transgenic Mouse Core

National Human Genome Research Institute

Investigators

Linked publications & trials

Abstract

The NHGRI Embryonic Stem Cell and Transgenic Mouse Core provides a shared service to NHGRI investigators. The Core specializes in generating genetically engineered mice (GEM) via conventional transgenesis, ES cell targeting, but primarily through genome editing using site-specific nucleases (CRISPR/Cas). To do this work, the Core breeds, in-house, 90% of the animals to be used for generating GEM. The Core utilizes several background strains for generating mice and has developed and characterized embryonic stem cells from C57Bl/6J, C57Bl/6N, C57Bl/6 albino, 129S6Sv/Ev, and 129.B6(GFP). We also have a colony of various Cre expressing mice and other transgenics that are used by investigators across many protocols, thereby maximizing the efficiency and reducing mouse numbers by breeding for multiple users. All important mice are cryopreserved and stored in 2 separate locations for disaster purposes. All imported mice are rederived into the Core by in vitro fertilization. We routinely genotype mice and have adapted efficient protocols to minimize mice, reagents and time. The Core supports NHGRI investigators in construct design for gene targeting/editing and transgenesis, and in basic manipulations of the mouse and husbandry. Other services provided by the Core to help serve NHGRI investigators include teratoma analysis, embryo harvest and dissection, isolation of mouse embryonic fibroblasts and generation of induced pluripotent stem cells. These services allow NHGRI investigators to take full advantage of the mouse as a model organism. Thus, the Core not only generates mice, but we facilitate and enable investigators to perform mouse experiments in areas where they have less expertise. The NHGRI Transgenic Core is at the forefront of a major increase in transgenic production using CRISPR/Cas gene-editing constructs via either injection or electroporation of fertilized eggs. More recently, the core has developed in house protocols for in vivo gene-editing and editing by electroporation with IVF generated embryos. These technologies are replacing the generation of conventional knockout mice using embryonic stem cells and has made the technology more user friendly to a variety of investigators and allows NHGRI to be at the cutting edge of this new and important genomic editing technology in mammalian models. The core has generated targeted transgenics using the CRISPR/Cas system for hundreds of constructs since the technology was first introduced in the mouse( October 2013). Additionally, more transgenic/ gene edited lines have been cryopreserved due to the efficiency of CRISPR/Cas to generate multiple alleles.