Generating Brown Adipocyte-Specific Atg7 KO Mice

All animal experiments were performed according to an approved protocol (approval number: 2016-12-139, approved date: 9 August 2016), from the Institutional Animal Care and Use Committee of Asan Life Science Institute, Asan Medical Center, Seoul, Korea. Mice were housed in a temperature-controlled pathogen-free facility under a 12 h/12 h light/dark cycle (lights on at 08:00) with free access to water and a normal chow diet (Purina Rodent Chow, Seoul, Korea). To establish brown adipocyte-specific Atg7 conditional knockout mice, Atg7^fl/fl mice [20 (link),46 (link)] were crossed with UCP1-CreER^+/− mice [21 (link)]. Tamoxifen (1 mg/5 g body weight) (Sigma-Aldrich, St. Louis, MO, USA) dissolved in corn oil (Sigma-Aldrich) was orally administered to their off-spring for five consecutive days. To ablate Atg7 from newly generated brown adipocytes, every fifth week Tamoxifen was regularly administered to mice for five consecutive days [21 (link)]. In this experiment, Atg7^fl/fl mice and Atg7^fl/fl-UCP1-CreER^+/− mice (ATG7B KO) were used as the control and experimental groups, respectively, and their body weights were monitored every week for 1 year. For diet-induced obesity—1 week after Tamoxifen administration—the normal chow diet was switched to a 60% HFD (D12492, Research Diets, New Brunswick, NJ, USA).