title: Conserved Noncoding Sequences Regulate lhx5 Expression in the Zebrafish Forebrain.
abstract: The LIM homeobox family protein Lhx5 plays important roles in forebrain development in the vertebrates. The lhx5 gene exhibits complex temporal and spatial expression patterns during early development but its transcriptional regulation mechanisms are not well understood. Here, we have used transgenesis in zebrafish in order to define regulatory elements that drive lhx5 expression in the forebrain. Through comparative genomic analysis we identified 10 non-coding sequences conserved in five teleost species. We next examined the enhancer activities of these conserved non-coding sequences with Tol2 transposon mediated transgenesis. We found a proximately located enhancer gave rise to robust reporter EGFP expression in the forebrain regions. In addition, we identified an enhancer located at approximately 50 kb upstream of lhx5 coding region that is responsible for reporter gene expression in the hypothalamus. We also identify an enhancer located approximately 40 kb upstream of the lhx5 coding region that is required for expression in the prethalamus (ventral thalamus). Together our results suggest discrete enhancer elements control lhx5 expression in different regions of the forebrain.
authors.affiliation: Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China.
authors.forename: Liu
authors.initials: L
authors.lastname: Sun
authors.affiliation: Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China.
authors.forename: Fengjiao
authors.initials: F
authors.lastname: Chen
authors.affiliation: Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Peng
mesh_terms: D000818:Animals; D017124:Conserved Sequence; D004742:Enhancer Elements, Genetic; D018507:Gene Expression Regulation, Developmental; D018014:Gene Transfer Techniques; D060850:LIM-Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D016548:Prosencephalon / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D015027:Zebrafish / Q000235:genetics* / Q000378:metabolism; D029961:Zebrafish Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D060850:LIM-Homeodomain Proteins; C514539:Lhx5 protein, zebrafish; D014157:Transcription Factors; D029961:Zebrafish Proteins