| First Author | Rucker EB | Year | 1997 |
| Journal | Mol Reprod Dev | Volume | 48 |
| Issue | 3 | Pages | 324-31 |
| PubMed ID | 9322243 | Mgi Jnum | J:43319 |
| Mgi Id | MGI:1097499 | Doi | 10.1002/(SICI)1098-2795(199711)48:3<324::AID-MRD4>3.0.CO;2-T |
| Citation | Rucker EB, et al. (1997) Cre-mediated recombination at the murine whey acidic protein (mWAP) locus. Mol Reprod Dev 48(3):324-31 |
| abstractText | The mouse whey acidic protein (WAP) gene in mouse embryonic stem (ES) cells has been targeted with a loxP-flanked neomycin phosphotransferase-thymidine kinase (neo-TK) cassette inserted into exon 4. Southern blot revealed that 51 of 199 colonies were correctly targeted (1:4). Next, a Cre-encoding plasmid was electroporated into a targeted cell line to cause the deletion of the neo-TK cassette. Modified ES cell colonies were identified by polymerase chain reaction (PCR); 44 out of 50 colonies (88%) had undergone Cre-mediated deletion. Finally, a loxP-tagged cell line was co-electroporated with a Cre-encoding plasmid and a loxP-containing neo plasmid for site-specific insertion into the WAP locus. The frequency of this event was 23% (11 of 48) of that obtained with random integration. This demonstrates the feasibility of using the Cre-loxP system for site-specific integration in ES cells. Moreover, this is the first report of targeting a loxP-containing transgene into a predetermined location in ES cells. Ultimately, a mouse model derived from these modified ES cells will usher in a second generation of animal bioreactor models where the inserted transgene is controlled exclusively by the endogenous locus regulatory elements. In addition, oncogenesis can be explored from single copy oncogene/tumor suppressor gene inserts, which are regulated in a temporal and tissue-specific manner. It is hoped that regulation of transgene expression in this fashion will help elucidate the underlying mechanisms of normal development in the mammary gland. |
