FIG. 1.

Experimental design. To investigate the preadipocyte and adipocyte phenotypes, RNA was purified from confluent 3T3-L1 preadipocytes (PA; day 0) and 3T3-L1 adipocytes that were 14 days postinduction (Ad; day 14). In addition, RNA was purified from mouse white adipose tissue (WAT) that had been separated into stromal vascular (SV) cells (which contain preadipocytes) and white adipocytes (WAd). To gain further insight into the early events of adipogenesis and the mechanism by which Wnt signaling blocks this differentiation process, 3T3-L1 cells were control infected (Control) or infected with a retrovirus encoding the gene for Wnt-1 (Wnt). Following selection, cells were induced to differentiate with methylisobutylxanthine, dexamethasone, and insulin (MDI) in 10% fetal calf serum. RNA was prepared from cells at 0, 16, 32, and 48 h following induction of differentiation. For each condition, RNA was purified from two independent samples, and transcript levels were measured by microarray with U74A Affymetrix chips, which represent approximately 10,000 distinct mouse genes and ESTs.