Chromosome localization analysis of genes strongly expressed in human visceral adipose tissue

To understand fully the physiologic functions of visceral adipose tissue and to provide a basis for the identification of novel genes related to obesity and insulin resistance, the gene expression profiling of human visceral adipose tissue was established by using cDNA array. The characterization and chromosome localization of 400 expressed sequence tags (ESTs) strongly expressed in visceral adipose tissue were analyzed by searching PubMed, UniGene, the Human Genome Draft Database, and Location Data Base. Two hundred eighty-nine clones were classified into known genes among the 400 ESTs strongly expressed in the tissue. Among them, <20% have been previously reported to be expressed in adipose tissue. The chromosome localization of 389 ESTs strongly expressed in visceral adipose tissue showed that their relative abundance was significantly increased on chromosomes 1, 16, 19, 20, and 22 compared with the expected distribution of the same number of random genes. The intrachromosome distribution of the genes strongly expressed in visceral adipose tissue was concentrated in certain regions, such as 1p36.2-1p36.3, 6p21.3-6p22.1, 19p13.3 and 19q13.1. Among them, the region of 1p36.2-1p36.3 appeared to be specific for visceral adipose tissue. Interestingly, some genes playing an important role in the pathogenesis of insulin signal transduction and adipocyte differentiation, such as tumor necrosis factor-alpha and its receptors; CCAAT/enhancer-binding protein-alpha; and phosphoinositide-3-kinase, regulatory subunit, polypeptide 2 (p85beta), were also localized in the concentrated regions, which may provide clues to identifying novel genes closely related to adipocyte function with potential pathophysiologic implications.