title: DeltaC and DeltaD interact as Notch ligands in the zebrafish segmentation clock.
abstract: We describe the production and characterisation of two monoclonal antibodies, zdc2 and zdd2, directed against the zebrafish Notch ligands DeltaC and DeltaD, respectively. We use our antibodies to show that these Delta proteins can bind to one another homo- and heterophilically, and to study the localisation of DeltaC and DeltaD in the zebrafish nervous system and presomitic mesoderm (PSM). Our findings in the nervous system largely confirm expectations from previous studies, but in the PSM we see an unexpected pattern in which the localisation of DeltaD varies according to the level of expression of DeltaC: in the anterior PSM, where DeltaC is plentiful, the two proteins are colocalised in intracellular puncta, but in the posterior PSM, where DeltaC is at a lower level, DeltaD is seen mainly on the cell surface. Forced overexpression of DeltaC reduces the amount of DeltaD on the cell surface in the posterior PSM; conversely, loss-of-function mutation of DeltaC increases the amount of DeltaD on the cell surface in the anterior PSM. These findings suggest an explanation for a long-standing puzzle regarding the functions of the two Delta proteins in the somite segmentation clock--an explanation that is based on the proposition that they associate heterophilically to activate Notch.
authors.affiliation: Vertebrate Development Laboratory, Cancer Research UK, 44 Lincoln's Inn Fields, London, UK.
authors.forename: Gavin J
authors.initials: GJ
authors.lastname: Wright
authors.forename: François
authors.initials: F
authors.lastname: Giudicelli
authors.forename: Cristian
authors.initials: C
authors.lastname: Soza-Ried
authors.forename: Anja
authors.initials: A
authors.lastname: Hanisch
authors.forename: Linda
authors.initials: L
authors.lastname: Ariza-McNaughton
authors.forename: Julian
authors.initials: J
authors.lastname: Lewis
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D017403:In Situ Hybridization; D047908:Intracellular Signaling Peptides and Proteins / Q000276:immunology / Q000378:metabolism*; D008565:Membrane Proteins / Q000276:immunology / Q000378:metabolism*; D008648:Mesoderm / Q000378:metabolism; D018613:Microscopy, Confocal; D009419:Nerve Tissue Proteins / Q000276:immunology / Q000378:metabolism*; D009420:Nervous System / Q000378:metabolism; D051880:Receptors, Notch / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*; D015027:Zebrafish / Q000196:embryology*; D029961:Zebrafish Proteins / Q000276:immunology / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D051880:Receptors, Notch; D011994:Recombinant Proteins; D029961:Zebrafish Proteins; C064045:delta protein; C468126:dld protein, zebrafish