Brief report: Musashi1-eGFP mice, a new tool for differential isolation of the intestinal stem cell populations

Authors

  • Francesca Maria Cambuli,

    1. Centre de Génétique et de Physiologie Moléculaire et Cellulaire, Université Claude Bernard, France
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  • Amélie Rezza,

    1. Centre de Génétique et de Physiologie Moléculaire et Cellulaire, Université Claude Bernard, France
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  • Julien Nadjar,

    1. Centre de Génétique et de Physiologie Moléculaire et Cellulaire, Université Claude Bernard, France
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  • Michelina Plateroti

    Corresponding author
    1. Centre de Génétique et de Physiologie Moléculaire et Cellulaire, Université Claude Bernard, France
    • Correspondence: Michelina Plateroti, Ph.D., Centre de Génétique et de Physiologie Moléculaire et Cellulaire, Université Lyon 1, 16 Rue Raphael Dubois, 69622 Villeurbanne, France. Telephone: 33–472431595; Fax: 33–472432685; e-mail: michelina.plateroti@univ-lyon1.fr

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  • Author contributions: F.C. and A.R.: conception and design, collection and assembly of data, data analysis and interpretation, and manuscript writing; J.N.: collection and assembly of data; M.P.: conception and design, financial support, assembly of data, data analysis and interpretation, manuscript writing, and final approval of the manuscript. All authors approved the manuscript. F.M.C. and A.R. contributed equally to this article.

Abstract

The intestinal epithelium self-renews rapidly and continuously throughout life, due to the presence of crypt stem cells. Two pools of these cells have been identified in the small intestine, which differ in position (“+4” or the bottom of the crypts), expression of specific markers (Bmi1/mTert or Lgr5/Ascl2), and cell cycle characteristics. Interestingly, the RNA-binding protein Musashi1 is expressed in both populations and therefore a potential marker for both stem cell types. In order to locate, isolate, and study Musashi1-expressing cells within the intestinal epithelium, we generated transgenic mice expressing GFP fluorescent protein under the control of a 7-kb Msi1 promoter. The expression pattern of GFP in the intestinal crypts of both small and large intestines completely overlapped that of Musashi1, validating our model. By using fluorescence-activated cell sorting, cellular, and molecular analyses, we showed that GFP-positive Msi1-expressing cells are divided into two major pools corresponding to the Lgr5- and mTert-expressing stem cells. Interestingly, monitoring the cell cycle activity of the two sorted populations reveals that they are both actively cycling, although differences in cell cycle length were confirmed. Altogether, our new reporter mouse model based upon Musashi1 expression is a useful tool to isolate and study stem cells of the intestinal epithelium. Moreover, these mice uniquely enable the concomitant study of two pools of intestinal stem cells within the same animal model. Stem Cells 2013;31:2273–2278

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