Expression of Cre recombinase in the mouse developing chondrocytes driven by the mouse α2(XI) collagen promoter

Spatial and temporal gene inactivation by the cre-loxP system is a powerful tool for analyzing genes of interests. We generated a transgenic mouse line that expresses Cre recombinase under the control of the -742-bp promoter sequence of the mouse α2(XI) collagen gene. Crossing this mouse line with a reporter mouse revealed that Cre recombinase activity is observed specifically in developing chondrocytes. This chondrocyte-specific Cre expression was observed from the early stage of chondrocyte differentiation in forelimb at 12.5 dpc, but not expressed in mesenchymal condensations. This transgenic mouse line will be a suitable resource for the analysis of gene function in differentiating chondrocytes and the mechanism of endochondral ossification.