Saunders S E, Kellett E, Bright K, Benjamin P R, Burke J F
Sussex Neuroscience Research Centre, School of Biological Sciences, University of Sussex, Brighton, United Kingdom.
J Neurosci. 1992 Mar;12(3):1033-9. doi: 10.1523/JNEUROSCI.12-03-01033.1992.
Individual neurons synthesize different peptide neurotransmitters and neuromodulators. In general, specificity is achieved by transcriptional regulation of neuropeptide-encoding genes. In Lymnaea, the FMRFamide and GDP/SDPFLRFamide neuropeptides are encoded by separate exons. Here we provide evidence that the two exons are part of the same gene and that in neurons expressing the gene the two exons are spliced onto a common upstream exon encoding a hydrophobic leader sequence. In addition, in situ hybridization data show that there is mutually exclusive cytoplasmic expression of each of the neuropeptide-encoding exons. Thus, differential neuropeptide synthesis is likely to be regulated by an alternative splicing mechanism. The cellular specificity of these splicing events is remarkable and suggests that cell-specific alternative splicing may be of major importance in establishing neuronal diversity in this system.
单个神经元合成不同的肽类神经递质和神经调质。一般来说，特异性是通过对神经肽编码基因的转录调控来实现的。在椎实螺中，FMRF酰胺和GDP/SDPFLRF酰胺神经肽由不同的外显子编码。在此我们提供证据表明，这两个外显子是同一基因的一部分，并且在表达该基因的神经元中，这两个外显子被剪接到一个共同的上游外显子上，该上游外显子编码一个疏水前导序列。此外，原位杂交数据表明，每个神经肽编码外显子在细胞质中的表达是相互排斥的。因此，不同的神经肽合成可能受可变剪接机制调控。这些剪接事件的细胞特异性很显著，表明细胞特异性可变剪接可能在建立该系统的神经元多样性方面具有重要意义。
