Rgs16 gene transcription regulated by fasting and refeeding. ( A ) Liver nuclei were prepared from fasted male C57BL/6 mice (n = 4/group; individually caged) at ZT5 on day 3 of RF, or refed for 20, 40, or 60 minutes. Liver nuclei from each condition were pooled prior to nuclear run-on. Nascent transcripts of radiolabeled RNA from nuclear run-ons were hybridized to plasmid cDNAs (5 μg) of mouse Rgs16, rat GAPDH, mouse Rgs8 or vector control. The relative transcriptional activity and QPCR assay of mRNA levels of Rgs16 in livers of fasted and refed mice is shown below the corresponding nuclear run-on blot. The results are representative of 3 separate experiments. ( B ) Changes in body weight and food intake during ad libitum (ad lib) and RF feeding in the male mice assayed in part A. Day 0, open bar indicates the average daily food consumption of ad libitum fed male mice (avg 27 g at start of experiment, n = 31 individually caged mice assayed over 4 days prior to RF); Day 1–2 (RF), open bar indicates total food consumed in 4 hr, ZT5–ZT9 (n = 31); Day 3 (RF), open bars indicate the amount of food consumed ad libitum, starting at ZT5 and feeding for 20, 40 or 60 min (n = 4/time point). ZT, Zeitgeber Time; RF, restricted feeding.