title: Identification and functional characterization of novel transcriptional enhancers involved in regulating human GLI3 expression during early development.
abstract: The zinc-finger transcription factor GLI3 acts as a primary transducer of Sonic hedgehog (Shh) signaling in a context-dependent combinatorial fashion. GLI3 participates in the patterning and growth of many organs, including the central nervous system (CNS) and limbs. Previously, we reported a subset of human intronic cis-regulators controlling many known aspects of endogenous Gli3 expression in mouse and zebrafish. Here we demonstrate in a transgenic zebrafish assay the potential of two novel tetrapod-teleost conserved non-coding elements (CNEs) docking within GLI3 intronic intervals (intron 3 and 4) to induce reporter gene expression at known sites of endogenous Gli3 transcription in embryonic domains such as the central nervous system (CNS) and limbs. Interestingly, the cell culture based assays reveal harmony with the context dependent dual nature of intra-GLI3 conserved elements. Furthermore, a transgenic zebrafish assay of previously reported limb-specific GLI3 transcriptional enhancers (previously tested in mice and chicken limb buds) induced reporter gene expression in zebrafish blood precursor cells and notochord instead of fin. These results demonstrate that the appendage-specific activity of a subset of GLI3-associated enhancers might be a tetrapod innovation. Taken together with our recent data, these results suggest that during the course of vertebrate evolution Gli3 expression control acquired a complex cis-regulatory landscape for spatiotemporal patterning of CNS and limbs. Comparative data from fish and mice suggest that the functional aspects of a subset of these cis-regulators have diverged significantly between these two lineages.
authors.affiliation: National Center for Bioinformatics, Computational Biology Lab, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan.
authors.forename: Saneela
authors.initials: S
authors.lastname: Anwar
authors.affiliation: National Center for Bioinformatics, Program of Comparative and Evolutionary Genomics, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan.
authors.forename: Rashid
authors.initials: R
authors.lastname: Minhas
authors.affiliation: National Center for Bioinformatics, Program of Comparative and Evolutionary Genomics, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan.
authors.forename: Shahid
authors.initials: S
authors.lastname: Ali
authors.affiliation: Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota, 55455, USA.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Lambert
authors.affiliation: Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota, 55455, USA.
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Kawakami
authors.affiliation: The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, London, NW7 1AA, UK.
authors.forename: Greg
authors.initials: G
authors.lastname: Elgar
authors.affiliation: National Center for Bioinformatics, Computational Biology Lab, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan.
authors.forename: Syed Sikandar
authors.initials: SS
authors.lastname: Azam
authors.affiliation: National Center for Bioinformatics, Program of Comparative and Evolutionary Genomics, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan.
authors.forename: Amir Ali
authors.initials: AA
authors.lastname: Abbasi
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified / Q000235:genetics / Q000378:metabolism; D004742:Enhancer Elements, Genetic / Q000235:genetics / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D051741:Kruppel-Like Transcription Factors / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015027:Zebrafish / Q000235:genetics / Q000378:metabolism*; D000074290:Zinc Finger Protein Gli3
chemical_list: C065683:GLI3 protein, human; D051741:Kruppel-Like Transcription Factors; D009419:Nerve Tissue Proteins; D014157:Transcription Factors; D000074290:Zinc Finger Protein Gli3
keywords: Cis-regulators; GLI3; conserved non-coding elements; enhancer; fin