TISSUE-SPECIFIC AND CELL-SPECIFIC EXPRESSION OF HUMAN SN-GLYCEROL-3-PHOSPHATE DEHYDROGENASE IN TRANSGENIC MICE

Comparison of the promoter sequence for the sn-glycerol-3-phosphate dehydrogenase (GPDH, EC 1.1.1.8) genes in mice and humans showed that there were three promoter domains conserved in evolution (1). To study the functional organization of the GPDH promoter, we generated transgenic mice carrying the complete human gene, GPD1. The level of human and mouse GPDH activity was measured in each tissue and the amount of human-mouse GPDH heterodimer was used as a sensitive indicator of cell-specific expression of GPD1. During postnatal development and in adult tissues of the transgenic mice, human GPDH was expressed at levels that corresponded closely to the expression of the endogenous mouse gene, Gdc-1. Surprisingly, deletion of the evolutionarily conserved fat-specific elements (FSE) in the proximal promoter region failed to reveal any alterations in GPD1 expression that were specific for either white or brown adipose tissue.