Figure 4. The structure of the cholinergic gene locus is conserved from C.

Figure 4

The structure of the cholinergic gene locus is conserved from C. elegans to mammals. In C. elegans, the unc-17 gene, which encodes the vesicular acetylcholine transporter (VAChT), is nested within the long first intron of the cha-1 gene, which encodes choline acetyltransferase (ChAT). Both genes use a common, 66-base untranslated 5′exon, with the cha-1 and unc-17 transcripts produced by alternative splicing (Alfonso et al. 1994b). A very similar gene organization has been observed in rats and humans (Bejanin et al. 1994; Erickson et al. 1994). For each organism, the genomic region is shown schematically (not necessarily to scale) above the structures of the transcripts so far identified. In mammals, three independent promoter regions (designated R, M, and N) have been identified, as well as exon-specific alternative splicing. This leads to several types of VAChT and ChAT transcripts which have not yet been identified in C. elegans. The start codon (ATG) is indicated for each gene. Most of the ChAT-coding exons are not shown.

From: Section II, Neurotransmitter Metabolism and Function

Cover of C. elegans II
C. elegans II. 2nd edition.
Riddle DL, Blumenthal T, Meyer BJ, et al., editors.
Cold Spring Harbor (NY): Cold Spring Harbor Laboratory Press; 1997.
Copyright © 1997, Cold Spring Harbor Laboratory Press.

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