A transgenic Lef1/beta-catenin-dependent reporter is expressed in spatially restricted domains throughout zebrafish development.
The Wnt/beta-catenin signaling pathway plays multiple roles during embryonic development, only a few of which have been extensively characterized. Although domains of Wnt expression have been identified throughout embryogenesis, anatomical and molecular characterization of responding cells has been mostly unexplored. We have generated a transgenic zebrafish line that expresses a destabilized green fluorescent protein (GFP) variant under the control of a beta-catenin responsive promoter. Early zygotic expression of this transgene (TOPdGFP) mirrors known domains of Wnt signaling in the embryo. Loss of Lef1 activity results in decreased reporter expression and posterior defects, while loss of Tcf3 (Headless, Hdl) activity does not alter reporter expression, even though it results in loss of forebrain structures. In addition, ectopic Wnt1 expression can activate the reporter. In older embryos, we identify a number of transgene-expressing cell populations as novel sites of beta-catenin signaling. We conclude that our TOP-dGFP reporter line faithfully illustrates domains of beta-catenin activity and enables the identification of responsive cell populations.
Dorsky
Richard I
RI
Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA.
Sheldahl
Laird C
LC
Moon
Randall T
RT
D000818:Animals; D030801:Animals, Genetically Modified; D001665:Binding Sites; D019521:Body Patterning / Q000235:genetics*; D001921:Brain / Q000196:embryology / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D004625:Embryo, Nonmammalian / Q000378:metabolism / Q000648:ultrastructure; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter; D005813:Genes, Synthetic; D016762:Genes, fos; D049452:Green Fluorescent Proteins; D024002:HMGB Proteins / Q000235:genetics / Q000502:physiology; D008164:Luminescent Proteins / Q000096:biosynthesis / Q000235:genetics; D051821:Lymphoid Enhancer-Binding Factor 1; D008845:Microinjections; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics; D020319:Oligodeoxyribonucleotides, Antisense / Q000494:pharmacology; D010857:Pigment Epithelium of Eye / Q000196:embryology / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D051820:TCF Transcription Factors; D013623:Tail / Q000196:embryology / Q000378:metabolism; D015534:Trans-Activators; D058125:Transcription Factor 7-Like 1 Protein; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic; D051153:Wnt Proteins; D051155:Wnt1 Protein; D015027:Zebrafish / Q000196:embryology; D029961:Zebrafish Proteins; D015053:Zygote / Q000378:metabolism / Q000648:ultrastructure; D051176:beta Catenin
D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins; D024002:HMGB Proteins; D008164:Luminescent Proteins; D051821:Lymphoid Enhancer-Binding Factor 1; D009419:Nerve Tissue Proteins; D020319:Oligodeoxyribonucleotides, Antisense; D011518:Proto-Oncogene Proteins; D011993:Recombinant Fusion Proteins; D051820:TCF Transcription Factors; D015534:Trans-Activators; D058125:Transcription Factor 7-Like 1 Protein; D014157:Transcription Factors; D051153:Wnt Proteins; D051155:Wnt1 Protein; D029961:Zebrafish Proteins; D051176:beta Catenin; C495269:ctnnb1 protein, zebrafish; C544914:tcf7l1a protein, zebrafish; C094522:wnt8b protein, zebrafish; D049452:Green Fluorescent Proteins