Protein products of the bacterial reporter gene are found within axon terminals in the brain of transgenic mice.

The aim of this study is to examine whether protein products of the bacterial reporter gene are localized within axon terminals in transgenic mice. We have previously created transgenic mice carrying a chimeric gene composed of the human tyrosine hydroxylase gene promoter and the bacterial gene encoding chloramphenicol acetyltransferase (CAT). In the present study, we used an antiserum that detects specifically CAT, and examined immunocytochemically the brain of the transgenic mice. At a light microscopic level, CAT immunoreactivity was found in a dense plexus of fibers in the central nucleus of the amygdala, and in cell bodies of the ventral tegmental area. At an electron microscopic level, in the central nucleus of the amygdala, CAT immunoreactivity was observed in axon terminals. In the ventral tegmental area, the immunoreactivity was found in the perikaryal cytoplasm and on the microtubule of dendrites. The present findings suggest that protein products of the bacterial gene may be transported in axons up to their terminals, and also moved along the microtubules of dendrites.