B6 cg speer6 ps1tg alb cre 21mgn j mice

C57BL/6J mice (RRID: IMSR_JAX:000664), B6;FVB-Tg(Adipoq-Cre)1Evdr mice (RRID: IMSR_JAX:028020) (Eguchi et al. 2011 (link)), and B6.Cg-Speer6-ps1^{Tg(alb-cre)21Mgn}/J mice (RRID: IMSR_ JAX:003574) (Postic et al. 1999 (link)) were obtained from The Jackson Laboratory. We have previously described Adipoq^−/− mice (Nawrocki et al. 2006 (link)), Fgf21^LoxP/LoxP mice (Vernia et al. 2016a (link)), Mapk8^LoxP/LoxP mice (Das et al. 2007 (link)), and Mapk9^LoxP/LoxP mice (Han et al. 2013 (link)). The mice were backcrossed to the C57BL/6J strain (10 generations) and housed in a specific pathogen-free facility accredited by the American Association for Laboratory Animal Care using laminar flow cages at 21°C. Mice were housed at thermoneutrality (30°C) in the vivarium using rodent incubators (Powers Scientific, Inc. model RIT33SD). Cold exposure was performed by reducing the temperature 2°C/day from ambient to the maintenance temperature (6°C) using rodent incubators in the vivarium. Male mice (age 8 wk) were fed a chow diet (Purina IsoPro 3000) or a high-fat diet (Bio-Serv S3282) (Han et al. 2013 (link)). Whole-body fat and lean mass were noninvasively measured by ¹H-MRS (Echo Medical Systems). The studies were approved by the Animal Care and Use Committees of the University of Massachusetts Medical School, Yale Medical School, and the University of Cincinnati.