Two zebrafish Notch-dependent hairy/Enhancer-of-split-related genes, her6 and her4, are required to maintain the coordination of cyclic gene expression in the presomitic mesoderm.
Alterations of the Delta/Notch signalling pathway cause multiple morphogenetic abnormalities in somitogenesis, including defects in intersomitic boundary formation and failure in maintenance of somite regularity. Notch signalling has been implicated in establishing the anteroposterior polarity within maturing somites and in regulating the activity of a molecular segmentation clock operating in the presomitic mesoderm. The pleiotropy of Notch signalling obscures the roles of this pathway in different steps of somitogenesis. One possibility is that distinct Notch effectors mediate different aspects of Notch signalling. In this study, we focus on two zebrafish Notch-dependent hairy/Enhancer-of-split-related transcription factors, Her6 and Her4, which are expressed at the transition zone between presomitic mesoderm and the segmented somites. The results of overexpression/gain-of-function and of morpholino-mediated loss-of-function experiments show that Her6 and Her4 are Notch signalling effectors that feedback on the clock and take part in the maintenance of cyclic gene expression coordination among adjacent cells in the presomitic mesoderm.
Pasini
Andrea
A
Division of Developmental Neurobiology, National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 7AA, UK.
Jiang
Yun-Jin
YJ
Wilkinson
David G
DG
D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D001683:Biological Clocks / Q000502:physiology; D019521:Body Patterning; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter; D018257:Helix-Loop-Helix Motifs; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D017403:In Situ Hybridization; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008648:Mesoderm / Q000166:cytology / Q000502:physiology*; D009024:Morphogenesis; D016376:Oligonucleotides, Antisense / Q000235:genetics / Q000378:metabolism; D051880:Receptors, Notch; D015398:Signal Transduction / Q000502:physiology; D019170:Somites / Q000502:physiology; D015534:Trans-Activators / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015027:Zebrafish / Q000196:embryology* / Q000235:genetics; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism*
D051792:Basic Helix-Loop-Helix Proteins; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D016376:Oligonucleotides, Antisense; D051880:Receptors, Notch; D015534:Trans-Activators; D014157:Transcription Factors; D029961:Zebrafish Proteins; C426854:Her6 protein, zebrafish; C064045:delta protein; C119433:her4.1 protein, zebrafish