title: Expression of conditional cre recombinase in epithelial tissues of transgenic mice.
abstract: Keratin 18 (K18) expression is a defining characteristic of internal epithelial cells of mammals. Here, we used the K18 gene and an internal ribosome entry site (IRES) to express green fluorescent protein, human placental alkaline phosphatase, and a modified Cre recombinase in an epithelial specific pattern in transgenic mice. The K18-driven alkaline phosphatase was expressed in liver, kidney, uterine endometrium, and other internal epithelia. The enzymatic activity of the Cre recombinase-mutant estrogen receptor fusion protein was dependent on tamoxifen administration and resulted in a mosaic pattern in internal epithelia, including bladder, uterus, liver, and kidney. This conditional Cre activity in internal epithelial organs should be valuable for strategies utilizing Cre for activation of gene expression. This study demonstrates that the tissue-specific, position-independent transcriptional activity of the K18 gene is not compromised by the use of an IRES element for the expression of a second protein from a bicistronic mRNA.
authors.affiliation: The Burnham Institute, La Jolla, California 92037, USA.
authors.forename: Fang
authors.initials: F
authors.lastname: Wen
authors.forename: Grace
authors.initials: G
authors.lastname: Cecena
authors.forename: Varinia
authors.initials: V
authors.lastname: Munoz-Ritchie
authors.forename: Elaine
authors.initials: E
authors.lastname: Fuchs
authors.forename: Pierre
authors.initials: P
authors.lastname: Chambon
authors.forename: Robert G
authors.initials: RG
authors.lastname: Oshima
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D004247:DNA / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D004848:Epithelium / Q000201:enzymology*; D004965:Estrogen Antagonists / Q000494:pharmacology; D005091:Exons; D049452:Green Fluorescent Proteins; D006801:Humans; D017403:In Situ Hybridization; D019426:Integrases / Q000096:biosynthesis* / Q000235:genetics*; D008164:Luminescent Proteins / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010920:Placenta / Q000201:enzymology; D012333:RNA, Messenger / Q000378:metabolism; D013629:Tamoxifen / Q000494:pharmacology; D013997:Time Factors; D014018:Tissue Distribution; D014764:Viral Proteins / Q000096:biosynthesis* / Q000235:genetics*; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D004965:Estrogen Antagonists; D008164:Luminescent Proteins; D012333:RNA, Messenger; D014764:Viral Proteins; D013629:Tamoxifen; D049452:Green Fluorescent Proteins; D004247:DNA; C045073:Cre recombinase; D019426:Integrases; D000469:Alkaline Phosphatase; D001616:beta-Galactosidase