title: Chemical genetics suggests a critical role for lysyl oxidase in zebrafish notochord morphogenesis.
abstract: As a result of a chemical genetic screen for modulators of metalloprotease activity, we report that 2-mercaptopyridine-N-oxide induces a conspicuous undulating notochord defect in zebrafish embryos, a phenocopy of the leviathan mutant. The location of the chemically-induced wavy notochord correlated with the timing of application, thus defining a narrow chemical sensitivity window during segmentation stages. Microscopic observations revealed that notochord undulations appeared during the phase of notochord cell vacuolation and notochord elongation. Notochord cells become swollen as well as disorganized, while electron microscopy revealed disrupted organization of collagen fibrils in the surrounding sheath. We demonstrate by assay in zebrafish extracts that 2-mercaptopyridine-N-oxide inhibits lysyl oxidase. Thus, we provide insight into notochord morphogenesis and reveal novel compounds for lysyl oxidase inhibition. Taken together, these data underline the utility of small molecules for elucidating the dynamic mechanisms of early morphogenesis and provide a potential explanation for the recently established role of copper in zebrafish notochord formation.
authors.affiliation: Centre for Regenerative Medicine, Department of Biology & Biochemistry, University of Bath, Bath, UKBA2 7AY.
authors.forename: Carrie
authors.initials: C
authors.lastname: Anderson
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Bartlett
authors.forename: John M
authors.initials: JM
authors.lastname: Gansner
authors.forename: Duncan
authors.initials: D
authors.lastname: Wilson
authors.forename: Ling
authors.initials: L
authors.lastname: He
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Gitlin
authors.forename: Robert N
authors.initials: RN
authors.lastname: Kelsh
authors.forename: James
authors.initials: J
authors.lastname: Dowden
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D004625:Embryo, Nonmammalian / Q000002:abnormalities / Q000201:enzymology; D008670:Metals / Q000378:metabolism; D015394:Molecular Structure; D009024:Morphogenesis / Q000235:genetics*; D009672:Notochord / Q000002:abnormalities / Q000187:drug effects / Q000196:embryology* / Q000201:enzymology; D008249:Protein-Lysine 6-Oxidase / Q000378:metabolism / Q000502:physiology*; D011725:Pyridines / Q000494:pharmacology; D013438:Sulfhydryl Compounds / Q000494:pharmacology; D013871:Thiones / Q000494:pharmacology; D013997:Time Factors; D015027:Zebrafish / Q000196:embryology* / Q000235:genetics
chemical_list: D008670:Metals; D011725:Pyridines; D013438:Sulfhydryl Compounds; D013871:Thiones; C008704:pyrithione; D008249:Protein-Lysine 6-Oxidase