Induction of the zebrafish ventral brain and floorplate requires cyclops/nodal signalling

摘要: Zebrafish cyclops (cyc) mutations cause deficiencies in the dorsal mesendoderm1,2 and ventral neural tube3,4, leading to defects cyclopia5,6. Here we report that cyc encodes a transforming growth factor-β (TGF-β)-related intercellular signalling molecule is similar mouse nodal7. expressed mesendoderm at gastrulation prechordal plate until early somitogenesis. Expression reappears transiently left lateral-plate mesoderm, an unprecedented asymmetric pattern forebrain. Injection of RNA non-autonomously restores sonic hedgehog -expressing cells brain floorplate are absent mutants, whereas inducing activities abolished by cycm294, mutation conserved cysteine mature ligand. Our results indicate provides essential non-cell-autonomous signal gastrulation, induction brain.