Keratin 14 Cre transgenic mice authenticate keratin 14 as an oocyte‐expressed protein

Abstract

Three mouse lines expressing Cre recombinase under the control of the human K14 promoter induced specific deletion of loxP flanked target sequences in the epidermis, in tongue, and thymic epithelium of the offspring where the Cre allele was inherited from the father. Where the mother carried the Cre allele, loxP flanked sequences were completely deleted in all tissues of the offspring, even in littermates that did not inherit the Cre allele. This maternally inherited phenotype indicates that the human K14 promoter is transcriptionally active in murine oocytes and that the enzyme remains active until after fertilization, even when the Cre allele becomes transmitted to the polar bodies during meiosis. Detection of K14 mRNA by RT-PCR in murine ovaries and immunohistochemical identification of the K14 protein in oocytes demonstrates that the human K14 promoter behaves like its murine homolog, thus identifying K14 as an authentic oocytic protein.

Monocytes/macrophages and/or neutrophils are the target of IL‐10 in the LPS endotoxemia model

“…1B). Deletion was found to be more than 90% efficient in T cells of IL-10R [13]. In our SPF mouse facility, neither conventional IL-10 [14] nor IL-10R1 knock-out mice were found to develop significant signs of inflammatory bowel disease when examined up to 12 months of age (data not shown).…”

Enhanced contact allergen- and UVB-induced keratinocyte apoptosis in the absence of CD95/Fas/Apo-1

“…20 Female mice homozygous or heterozygous for the floxed (Fl) Fas allele were bred to male mice homozygous or heterozygous for the Fl Fas allele and expressing Cre recombinase under the control of the keratin 14 promoter. 21 Samples of epidermis from ear and back skin as well as total tissue lysates from mouse tails for comparison were analyzed for the presence of wild-type and mutant Fas DNA (Supplementary Figure 1a) and of Fas protein using PCR and western blotting, respectively. Whereas epidermal samples from ear and back skin showed complete deletion of Fl Fas alleles, Fas was readily detected in total tissue lysates from tails ( Figure 1a; Supplementary Figure 1b (Figure 1b and d).…”

“…20 These mice were crossed with mice expressing Cre recombinase under the control of the keratin 14 promoter. 21 Deletion of Fl Fas alleles and presence of the Cre recombinase transgene were analyzed by PCR as described therein. For UVB treatment mice were anesthetized, shaved on their backs and irradiated with a dose of 300 mJ/cm 2 UVB using a Waldmann UV 801 lamp (Waldmann, Villingen-Schwenningen, Germany) equipped with UV21 bulbs emitting UV light in the range of 280-360 nm with an emission maximum at about 314 nm.…”

Genetic mouse models for skin research: Strategies and resources

“…However, in order to avoid unpleasant surprises and undesired side effects, researchers should obtain in advance as much information as possible about the characteristics of the line to be employed and pay attention to drawbacks and peculiarities of the available strategies. For example, since both K5 (Ramirez et al, 2004) and K14 (Hafner et al, 2004) are expressed in oocytes, constitutive Cre-mediated recombination has been reported when the Cre transgene is transmitted by the mother. While recombination in the oocytes has not been reported for every published K5-Cre or K14-Cre line, it is recommendable to use only Cre-positive males for mating in order to avoid a maternal deleter phenotype when employing these promoters.…”