title: High-efficiency somatic mutagenesis in smooth muscle cells and cardiac myocytes in SM22alpha-Cre transgenic mice.
abstract: The cytoskeletal protein SM22alpha is expressed in visceral and vascular smooth muscle cells (SMCs), in cardiac myocytes, and in the myotomal components of the somites during murine embryonic development. In this report, we describe the generation and characterization of transgenic mice expressing Cre-recombinase under the transcriptional control of the -2.8-kb SM22alpha promoter. Following interbreeding with the R26R reporter strain, Cre-dependent beta-galactosidase expression was observed as early as embryonic day 9.5 in SMCs of the developing vasculature, in cardiac myocytes, but not in the somites. In adult mice, Cre-mediated recombination was observed in vascular SMCs throughout the venous and arterial systems, in visceral SMCs in multiple organs, and in cardiac, but not skeletal muscle. Importantly, Cre-mediated recombination was present in nearly 100% of arterial SMCs, including in the aorta. These mice are thus an important new tool for performing in vivo loss-of-function studies of genes expressed in vascular SMCs.
authors.affiliation: Molecular Cardiology Research Center, Department of Medicine, University of Pennsylvania Health System, Philadelphia, Pennsylvania 19104, USA. john.lepore@uphs.upenn.edu
authors.forename: John J
authors.initials: JJ
authors.lastname: Lepore
authors.forename: Lan
authors.initials: L
authors.lastname: Cheng
authors.forename: Min
authors.initials: M
authors.lastname: Min Lu
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Mericko
authors.forename: Edward E
authors.initials: EE
authors.lastname: Morrisey
authors.forename: Michael S
authors.initials: MS
authors.lastname: Parmacek
mesh_terms: D000818:Animals; D002319:Cardiovascular System / Q000254:growth & development*; D005260:Female; D019426:Integrases / Q000378:metabolism; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D008840:Microfilament Proteins / Q000235:genetics* / Q000502:physiology*; D023421:Models, Animal; D009124:Muscle Proteins / Q000235:genetics* / Q000502:physiology*; D009131:Muscle, Smooth, Vascular / Q000166:cytology*; D016296:Mutagenesis; D032383:Myocytes, Cardiac; D011995:Recombination, Genetic; D001616:beta-Galactosidase / Q000096:biosynthesis*
chemical_list: D008840:Microfilament Proteins; D009124:Muscle Proteins; C051615:transgelin; C045073:Cre recombinase; D019426:Integrases; D001616:beta-Galactosidase