Transient Gene Knock-Out Model

**Semantic type:** Experimental Model of Disease

**Definition:** Conditional (or inducible) gene knock-out. A transgenic technique. A transgenic animal is constructed such that a gene of interest, or chromosome region, is flanked by recombination-signal sites (eg, loxP). The animal is then crossed to one which carries the specific recombinase (eg, cre) under the control of a conditional, or tissue specific, promoter. Upon treatment of an inducer the recombinase is expressed, promoting recombination between the signal sites and the loss of the intervening gene or chromosome region. (NCI/OSP)