Complementary DNAs for choline acetyltransferase from spinal cords of rat and mouse: nucleotide sequences, expression in mammalian cells, and in situ hybridization.

Complementary DNA clones containing the entire coding region of choline acetyltransferase (ChAT) were isolated from the spinal cords of rat and mouse. The cDNAs of rat and mouse coded for 640 and 641 amino acids, respectively, and showed 95% mutual homology and 80% homology with the cDNA of porcine ChAT. Northern blot analysis revealed a single band of 4.4 kb in the spinal cord and brain in each species. Introduction of the cDNAs into Chinese hamster ovary cells and neuron-derived cell lines, N1E115 and NG108-15, expressed a high ChAT activity, which was inhibited by a specific ChAT inhibitor. In situ hybridization using the rat cRNA probe revealed specific labeling of the motoneurons in the spinal cord and neurons in various forebrain nuclei of the rat where the existence of cholinergic neurons has been demonstrated immunohistochemically.