Developmentally regulated cDNA expressed exclusively in neural tissue.

A cDNA clone, labeled Cl-13, isolated from an adult rat brain cDNA library, has been characterized and found by Northern blot and S1 nuclease mapping experiments to be solely expressed in neuronal tissue, principally, but not exclusively, in the brain. The associated mRNA is first detected in embryonic life, reaches maximum levels of expression at birth, and remains expressed in the adult. Northern blot analysis shows the transcript is not localized to one particular area of the brain, but is present in numerous regions. Low message levels of this transcript are also found in the peripheral nervous system, demonstrating that the expression of the associated gene is not restricted to the central nervous system. In addition, results indicate expression is limited to neuronal cells, and is not detected in glia. The identification of the cDNA clone Cl-13, which possesses limited nucleotide homology to tropomyosin, is exciting, particularly considering the neural-specific expression that it manifests and the unique cytoskeletal and motile properties exhibited by neurons.