Tamoxifen‐inducible Cre‐mediated recombination in adipocytes

To generate a mouse line which allows inducible, Cre/loxP‐dependent recombination in adipocytes, we used RedE/RedT‐mediated recombineering to insert the CreER T2 ‐transgene, which encodes a fusion protein of Cre and a mutated tamoxifen‐responsive estrogen receptor, into the start codon of the adipocyte‐specific Adipoq gene. Adipoq encodes adiponectin, an adipokine specifically expressed in differentiated adipocytes. Tamoxifen treatment induced almost complete recombination in white adipose tissue of the Adipoq CreER T2 mouse line (97%–99%), while no recombination was seen in vehicle‐treated animals. Recombination in brown adipose tissue was about 15%, whereas other organs and tissues did not undergo recombination. In addition, mice expressing CreER T2 in adipocytes did not show any alterations of metabolic functions like glucose tolerance, lipolysis, or energy expenditure compared to control mice. Therefore the Adipoq CreER T2 mouse line will be a valuable tool for studying the consequences of a temporally controlled deletion of floxed genes in white adipose tissue. genesis 48:618–625, 2010.