PERIPHERAL NERVOUS SYSTEM-SPECIFIC GENES IDENTIFIED BY SUBTRACTIVE CDNA CLONING

An improved method for constructing and screening subtractive cDNA lib raries has been used to identify 46 mRNA transcripts that are expresse d selectively in neonatal rat dorsal root ganglia (DRG) as judged by N orthern blots and in situ hybridization. Sequence analysis demonstrate s that both known (e.g. peripherin, calcitonin gene-related peptide, m yelin PO) and novel identifiable transcripts (e.g. C-protein-like, syn uclein-like, villin-like) are present in the library. Half of the tran scripts (23) are undetectable in liver, kidney, heart, spleen, cerebel lum, and cerebral cortex, Of the DRG-specific transcripts, 12 contain putative open reading frames that show no identity with known proteins . The construction of such a subtractive library thus provides us with both known and novel markers, and identifies new predicted DRG-specif ic proteins. In addition, the DRG-specific clones provide probes to de fine the regulatory elements that specify peripheral nervous-system-sp ecific gene expression.