MONITORING CATECHOLAMINE DIFFERENTIATION IN THE EMBRYONIC BRAIN AND PERIPHERAL NEURONS USING ESCHERICHIA-COLI LACZ AS A REPORTER GENE

An X-gal based histochemical assay was used to detect catecholamine (C A) cells in transgenic mouse embryos, in which the expression of the l acZ reporter was driven by the tissue-specific promoter of the rat tyr osine hydroxylase (TH) gene, As the first enzyme in the biosynthetic p athway for CA neurotransmitters, TH is a specific phenotypic marker fo r CA cells in the central and peripheral nervous systems of adult anim als, During embryogenesis, TH expression appears permanently within CA -producing cells, and transiently within several other cell types. In this study we were able to monitor TH expression in transgenic mouse e mbryos by following the expression of the lacZ reporter in substantia nigral dopaminergic neurons in the central nervous system, the trigemi nal (V) sensory ganglia, and dorsal root ganglia in the periphery. Our results demonstrate that the rat TH promoter-lacZ transgene provides an important experimental tool for monitoring catecholaminergic lineag e cells during embryogenesis.