A tamoxifen-inducible chimeric Cre recombinase specifically effective in the fetal and adult mouse liver

Authors

  • Mounia Tannour-Louet,

    1. Institut Cochin U567, Département de Génétique, Développement et Physiopathologie Moléculaires, INSERM U129, Paris, France
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  • Arlette Porteu,

    1. Institut Cochin U567, Département de Génétique, Développement et Physiopathologie Moléculaires, INSERM U129, Paris, France
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  • Sophie Vaulont,

    1. Institut Cochin U567, Département de Génétique, Développement et Physiopathologie Moléculaires, INSERM U129, Paris, France
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  • Axel Kahn,

    1. Institut Cochin U567, Département de Génétique, Développement et Physiopathologie Moléculaires, INSERM U129, Paris, France
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  • Mireille Vasseur-Cognet

    Corresponding author
    1. Institut Cochin U567, Département de Génétique, Développement et Physiopathologie Moléculaires, INSERM U129, Paris, France
    • Institut Cochin U567, Département de Génétique, Développement et Physiopathologie Moléculaires, INSERM U567, 24 rue du Faubourg Saint Jacques, 75014 Paris, France. fax: (33) 1-44-41-24-21.
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Abstract

The spatiotemporal control of somatic mutagenesis in mice is considered a promising step to determine the function of a given gene product in a defined population of cells at any given time during animal life and also to generate better mouse models of human diseases. To introduce defined mutations in a temporally controlled manner in the liver, we established transgenic mice expressing a tamoxifen-inducible Cre recombinase under the control of the transthyretin promoter (TTR-Cre ind). The recombinase activity was examined on 2 different floxed alleles by crossing TTR-Cre ind mice with either the reporter strain ROSA 26 or with homozygous mice carrying floxed catalytic α2 subunit of the adenosine monophosphate (AMP)-activated protein kinase gene. By placing 2 mutated hormone-binding domains of murine estrogen receptor (Mer) at both termini of the Cre, we show that the fusion protein is active only on administration of the synthetic estrogen antagonist 4-hydroxytamoxifen (4-OHT) without any background in the absence of the inducing agent. The recombination is specific of the fetal and adult liver, and we show that the efficiency of recombination reached 80% to 100% after treatment with 4-OHT. In conclusion, TTR-Cre ind transgenic mice represent a valuable tool for temporally controlling the desired gene modifications in vivo in the fetal and adult liver. This would certainly help to understand the physiologic functions of genes in the liver, to create various mouse models mimicking human diseases, and to contribute to liver cancer–specific suicide gene therapy studies.

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