Tissue and cell type specificity of the human neurotrophin-3 promoter region in transgenic mice.
To examine the tissue and cell type specificity of the human neurotrophin-3 (NT-3) promoter, we generated transgenic mice bearing the 3.3 kbp upstream region of the human NT-3 gene linked to the bacterial chloramphenicol acetyltransferase (CAT) gene as a reporter. Eight independent founders of transgenic mice were obtained, and four of them transmitted the transgene to their offsprings. Among three lines of four transgenic mice at 6 weeks of age, a high level of production of CAT protein was detected in the spleen and a low level in the brain. By in situ hybridization analysis, CAT gene expression was detected in the hippocampal neurons and in the cerebellar granular neurons of the transgenic mouse brain. These results suggest that the 3.3 kbp 5' flanking region of the human NT-3 gene has adequate promoter activity in vivo and that its expression pattern resembles the endogenous gene.