Differential gene expression in white and brown preadipocytes

White (WAT) and brown (BAT) adipose tissue are tissues of energy storage an d energy dissipation, respectively. Experimental evidence suggests that bro wn and white preadipocytes are differentially determined, but so far not mu ch is known about the genetic control of this determination process. The ai m of this study was to identify differentially expressed genes involved in brown and white preadipocyte development. Using representational difference analysis (cDNA RDA) and DNA microarray screening, we identified four genes with higher expression in white preadipocytes (three different complement factors and delta -6 fatty acid desaturase) and seven genes with higher exp ression levels in brown preadipocytes, of which three are structural genes implicated in cell adhesion and cytoskeleton organization (fibronectin, alp ha -actinin-4, metargidin) and four that might function in gene transcripti on and protein synthesis (vigilin, necdin, snRNP polypeptide A, and a homol og to human hepatocellular carcinoma-associated protein). The expression pr ofile of these genes was analyzed during preadipocyte differentiation, upon beta -adrenergic stimulation, and in WAT and BAT tissue in vivo compared w ith references genes such as peroxisome proliferator-activated receptor-gam ma (PPAR gamma), uncoupling protein 1 (UCP1), cytochrome c oxidase.