Interestingly, and in contrast, the
induction of thermogenic genes in the s.c. (inguinal) fat in the
β-less mice was largely preserved on cold exposure (Fig. 1B),
suggesting there is a β-AR–independent pathway that controls
thermogenic gene expression in the s.c. fat. In the visceral (epididymal)
fat, although a β3 agonist caused a β-AR-dependent
thermogenic response, cold exposure did not lead to significant
induction of thermogenic gene expression, as it did in the s.c. fat,
suggesting the β-AR–independent thermogenic response is limited
to the s.c. fat (Fig. 1C).