The Transgenic and Genome Editing Core can develop mice with targeted mutations in the entire mouse or in specific tissues or cell types. It normally takes about a year to generate a gene-targeted mouse. Gene-targeted mouse ES cells are produced by electroporating a gene targeting construct into wild-type ES cells. The targeting construct typically contains selectable markers surrounded by two regions of homology to the targeted locus. In a fraction of those cells that take up the targeting construct, homologous recombination between the genome of the ES cell and the two regions of homology will result in the replacement of the targeted locus with the targeting construct.
Knock-out or knock-in mice are created by microinjecting these gene-targeted mouse ES cells into mouse blastocysts. The injected blastocysts are then transferred to pseudopregnant females and allowed to develop to term. The resulting pups are chimeras. The chimeras are then bred to establish the knockout mouse line.
Lin Gan, PhD
Director, Genome Editing Core
Knock-in/conditional knockout mice by gene targeting in ESCs
Production of mouse chimeras by microinjection of KOMP/EUCOMM ESC clones
ESC clone expansion