Lessons on Conditional Gene Targeting in Mouse Adipose Tissue
- Kevin Y. Lee1,
- Steven J. Russell1,
- Siegfried Ussar1,
- Jeremie Boucher1,
- Cecile Vernochet1,
- Marcelo A. Mori1,
- Graham Smyth1,
- Michael Rourk1,
- Carly Cederquist1,
- Evan D. Rosen2,
- Barbara B. Kahn2 and
- C. Ronald Kahn1⇓
- 1Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts
- 2Division of Endocrinology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
- Corresponding author: C. Ronald Kahn, .
Conditional gene targeting has been extensively used for in vivo analysis of gene function in adipocyte cell biology but often with debate over the tissue specificity and the efficacy of inactivation. To directly compare the specificity and efficacy of different Cre lines in mediating adipocyte specific recombination, transgenic Cre lines driven by the adipocyte protein 2 (aP2) and adiponectin (Adipoq) gene promoters, as well as a tamoxifen-inducible Cre driven by the aP2 gene promoter (iaP2), were bred to the Rosa26R (R26R) reporter. All three Cre lines demonstrated recombination in the brown and white fat pads. Using different floxed loci, the individual Cre lines displayed a range of efficacy to Cre-mediated recombination that ranged from no observable recombination to complete recombination within the fat. The Adipoq-Cre exhibited no observable recombination in any other tissues examined, whereas both aP2-Cre lines resulted in recombination in endothelial cells of the heart and nonendothelial, nonmyocyte cells in the skeletal muscle. In addition, the aP2-Cre line can lead to germline recombination of floxed alleles in ∼2% of spermatozoa. Thus, different “adipocyte-specific” Cre lines display different degrees of efficiency and specificity, illustrating important differences that must be taken into account in their use for studying adipose biology.
This article contains Supplementary Data online at http://diabetes.diabetesjournals.org/lookup/suppl/doi:10.2337/db12-1089/-/DC1.
- Received August 16, 2012.
- Accepted December 2, 2012.
- © 2013 by the American Diabetes Association.
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