Efficient Temporally-Controlled Targeted Mutagenesis in Smooth Muscle Cells of the Adult Mouse

To generate temporally-controlled targeted somatic mutations selectively and efficiently in smooth muscles, we have established a transgenic SMA-Cre-ERT2 mouse line in which the expression of the Tamoxifen-dependent Cre-ERT2 recombinase is under the control of a large genomic DNA segment of the mouse smooth muscle alpha actin (SMA) gene, contained in a Bacterial artificial chromosome (Bac). In this transgenic mouse line, Cre-ERT2-mediated recombination of LoxP-flanked target DNA is strictly Tamoxifen-dependent, and efficient in both vascular and visceral smooth muscle cells. Moreover, with the exception of few cardiomyocytes, LoxP-flanked DNA excision is restricted to smooth muscle cells. Thus, SMA-Cre-ERT2 mice should be of great value to analyze gene function in smooth muscles, and to establish new animal models of human smooth muscle disorders. genesis 47:14-18, 2009. (C) 2008 Wiley-Liss, Inc.