Rapid postprandial decline of Rgs16 mRNA and protein in liver. ( A ) Time course of Rgs16 mRNA and protein degradation in liver upon feeding at the beginning of the dark phase (ZT12). Food was removed from individually caged mice (female C57BL/6) at ZT4. Mice were fasted (time = 0) or refed for the indicated time (minutes), starting from ZT12. After sacrifice, liver samples were collected for mRNA and protein assays. Total liver protein and RNA was prepared from pooled samples of equal amount within each time point for Western blot and QPCR analysis, respectively (n = 3 mice/group). All mice had free access to water; 12 hr L:D. ( B ) Rgs16 mRNA and protein in liver of fasted mice is induced to different levels in mice maintained on normal chow or a high fat diet. Mice were maintained on high fat diet (Hi-Fat) for 7 weeks. Mice were fasted from ZT4 to ZT16 or ad libitum fed with normal chow from ZT12. Liver was collected at ZT16. Rgs16 protein expression was assayed by Western blot (bottom) and QPCR. Rgs16 mRNA and protein were individually assayed and quantitated by QPCR (filled bar) and Western blot densitometry (open bar; n = 3 mice/group) relative to pooled samples from fed mice. All mice (female C57BL/6) had free access to water; 12 hr L:D. ZT, Zeitgeber Time.