title: Abundant LacZ activity in the absence of Cre expression in the normal and inflamed synovium of adult Col2a1-Cre; ROSA26RLacZ reporter mice.
abstract: Recent analyses of Col2a1-Cre; ROSA26R reporter mice showed that synovial fibroblasts in 7-day mice were LacZ positive, due to a history of Col2a1-Cre expression conferred by their origin in the interzone of the developing joint. We have examined LacZ staining in adult Col2a1-Cre(+/0); ROSA26R(LacZ) mice, with and without inflammatory arthritis, and found that synovial fibroblasts in normal and inflamed synovium are LacZ positive, but Cre negative. Our results suggest that Cre-mediated recombination in joint interzone cells during development endure in adult synovial cells despite the absence of ongoing Cre expression. These findings have important implications and applications for the study of synovial inflammation in models of experimental arthritis.
authors.affiliation: University of Melbourne, Department of Paediatrics and Murdoch Childrens Research Institute, Parkville, Victoria 3052, Australia. amanda.fosang@mcri.edu.au
authors.forename: A J
authors.initials: AJ
authors.lastname: Fosang
authors.forename: S B
authors.initials: SB
authors.lastname: Golub
authors.forename: C J
authors.initials: CJ
authors.lastname: East
authors.forename: F M
authors.initials: FM
authors.lastname: Rogerson
mesh_terms: D000818:Animals; D001168:Arthritis / Q000473:pathology / Q000503:physiopathology*; D024043:Collagen Type II / Q000235:genetics / Q000502:physiology*; D004195:Disease Models, Animal; D005347:Fibroblasts / Q000473:pathology / Q000502:physiology; D005786:Gene Expression Regulation / Q000502:physiology; D017930:Genes, Reporter / Q000235:genetics / Q000502:physiology*; D019426:Integrases / Q000172:deficiency* / Q000235:genetics / Q000502:physiology; D007719:Knee Joint; D007763:Lac Operon / Q000235:genetics / Q000502:physiology*; D051379:Mice; D008822:Mice, Transgenic; D011506:Proteins / Q000235:genetics / Q000502:physiology*; D022661:RNA, Untranslated; D013583:Synovial Membrane / Q000473:pathology / Q000503:physiopathology*; D013997:Time Factors
chemical_list: C447413:Col2a1 protein, mouse; D024043:Collagen Type II; C110853:Gt(ROSA)26Sor non-coding RNA, mouse; D011506:Proteins; D022661:RNA, Untranslated; C045073:Cre recombinase; D019426:Integrases