Jia SJ, Ren Z, Li X, Zheng Y, Meng AM. smad2 and smad3 are required for mesendoderm induction by TGF-/Nodal signals in zebrafish. JOURNAL OF BIOLOGICAL CHEMISTRY 283(4):2418-2426, 2008

Abstract The transforming growth factor-beta ligands Nodal, activin, and Vg1 play important roles in mesendoderm induction and patterning during vertebrate embryogenesis. These ligands are believed to transduce the signal through the receptor-activated transcription factors Smad2 and Smad3. However, the roles of smad2/3 genes in development of zebrafish embryos are largely unknown because the presence of multiple smad2/3 genes and their maternal expression have hampered the investigation of their developmental roles. We generated potent and specific dominant-negative forms of zebrafish Smad2, Smad3a, and Smad3b by mutating multiple amino acids. Overexpression of these mutants abolished mesendoderm induction by ectopic Nodal signaling in zebrafish embryos. Expression of dominant-negative s......