Vol. 93, pp. 10887–10890, October 1996 | R. Feil, J. Brocard, B. Mascrez, M. LeMeur, D. Metzger, and P. Chambon*
The study reports the development of a conditional site-specific recombination system in mice using a new version of the Cre/loxP system. The researchers fused the Cre recombinase to a mutated ligand-binding domain of the human estrogen receptor (ER), creating a tamoxifen-dependent Cre recombinase (Cre-ERT). This system was expressed under the control of a cytomegalovirus promoter in transgenic mice. Administration of tamoxifen to these mice induced the excision of a chromosomally integrated gene flanked by loxP sites, while no excision was detected in untreated animals. The study demonstrates that this conditional system allows for the timed and tissue-specific inactivation of target genes, overcoming limitations of conventional gene targeting methods. The system could be used to analyze knockout phenotypes that are not accessible with conventional techniques, particularly in cases where gene inactivation results in intrauterine lethality or other developmental issues.The study reports the development of a conditional site-specific recombination system in mice using a new version of the Cre/loxP system. The researchers fused the Cre recombinase to a mutated ligand-binding domain of the human estrogen receptor (ER), creating a tamoxifen-dependent Cre recombinase (Cre-ERT). This system was expressed under the control of a cytomegalovirus promoter in transgenic mice. Administration of tamoxifen to these mice induced the excision of a chromosomally integrated gene flanked by loxP sites, while no excision was detected in untreated animals. The study demonstrates that this conditional system allows for the timed and tissue-specific inactivation of target genes, overcoming limitations of conventional gene targeting methods. The system could be used to analyze knockout phenotypes that are not accessible with conventional techniques, particularly in cases where gene inactivation results in intrauterine lethality or other developmental issues.