ZFIN ID: ZDB-PUB-090921-13
Cis-acting elements responsible for dopaminergic neuron-specific expression of zebrafish slc6a3 (dopamine transporter) in vivo are located remote from the transcriptional start site
Bai, Q., and Burton, E.A.
Date: 2009
Source: Neuroscience   164(3): 1138-1151 (Journal)
Registered Authors: Burton, Edward A.
Keywords: zebrafish, dopamine transporter, transgenic, enhancer, transcription, slc6a3, Parkinson's disease, dystonia, pretectal nucleus, DAT
MeSH Terms:
  • Amino Acid Sequence/genetics
  • Animals
  • Animals, Genetically Modified
  • Base Sequence/genetics
  • Binding Sites/genetics
  • Cell Differentiation/genetics
  • Conserved Sequence/genetics
  • Dopamine/metabolism*
  • Dopamine Plasma Membrane Transport Proteins/genetics*
  • Dopamine Plasma Membrane Transport Proteins/isolation & purification
  • Dopamine Plasma Membrane Transport Proteins/metabolism
  • Enhancer Elements, Genetic/genetics
  • Gene Expression Regulation/genetics
  • Gene Expression Regulation, Developmental/genetics
  • Mesencephalon/cytology
  • Mesencephalon/embryology
  • Mesencephalon/metabolism*
  • Molecular Sequence Data
  • Neurons/cytology
  • Neurons/metabolism*
  • Phenotype
  • Promoter Regions, Genetic/genetics
  • Regulatory Elements, Transcriptional/genetics
  • Regulatory Sequences, Nucleic Acid/genetics
  • TATA Box/genetics
  • Transcription Initiation Site/physiology
  • Zebrafish/genetics*
  • Zebrafish/metabolism
  • Zebrafish Proteins/genetics*
  • Zebrafish Proteins/isolation & purification
  • Zebrafish Proteins/metabolism
PubMed: 19755139 Full text @ Neuroscience
ABSTRACT
The purpose of this study was to analyze the transcriptional regulation of the zebrafish solute carrier family 6 member 3 gene ( slc6a3, dopamine transporter, dat), as a first step towards isolating regulatory sequences useful for driving transgene expression within dopaminergic neurons of the zebrafish central nervous system (CNS) in vivo. We found that the 3.0kb slc6a3 mRNA is expressed in each of the major groups of dopaminergic neurons previously identified in the zebrafish CNS. The slc6a3gene spans >20kb of genomic DNA and contains 15 exons. The genomic organization of slc6a3is highly conserved with respect to its human orthologue, including the presence of an untranslated first exon. The promoter lacks a canonical TATA box and there are multiple transcriptional start sites. Functional analysis of cis -acting elements responsible for the expression pattern of slc6a3was carried out by generating stable transgenic zebrafish lines expressing fluorescent reporters under transcriptional control of fragments of slc6a3genomic sequence. The region between -2kb and +5kb with respect to the transcriptional start site contains the core slc6a3promoter, in addition to neuronal enhancers and/or non-neuronal repressors that restrict expression to the CNS, but this region lacks cis -acting elements responsible for slc6a3expression in dopaminergic neurons. The upstream sequence between -6kb and -2kb contains an enhancer element that drives slc6a3expression in dopaminergic neurons of the pretectal region, and additional sequences that partially repress expression in non-dopaminergic neurons. However, expression of slc6a3in dopaminergic neurons of the ventral diencephalon and telencephalon is dependent on elements that lie outside the region -6kb to +5kb. These data provide a detailed analysis of the slc6a3gene and show that its expression in different populations of dopamine neurons is driven by discrete enhancers, rather than a single target sequence for a terminal factor involved in specifying neurochemical phenotype.
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