Ectopic expression of the proto-oncogene int-1 in Xenopus embryos leads to duplication of the embryonic axis.
While there is convincing evidence implicating Drosophila int-1 in pattern regulation, the normal role of int-1 in vertebrate development is unclear. We have injected Xenopus eggs with mouse int-1 RNA and monitored subsequent development. Injected RNA is translated and the protein widely distributed. Embryos develop into apparently normal gastrulae, but almost all surviving neurulae have a bifurcated anterior and expanded posterior neural plate. Bifurcation of the neural plate was abolished by substitution of a single, conserved cysteine residue and was dependent on the presence of a signal peptide sequence in the int-1 protein. Histological examination indicates that underlying axial mesodermal structures were duplicated. This result suggests that ectopic int-1 expression leads to dual axis formation and points to a role for int-1 in patterning processes in vertebrate development.
McMahon
A P
AP
Department of Cell and Developmental Biology, Roche Institute of Molecular Biology, Roche Research Center, Nutley, New Jersey 07110.
Moon
R T
RT
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D004625:Embryo, Nonmammalian / Q000502:physiology*; D051379:Mice; D008969:Molecular Sequence Data; D009420:Nervous System / Q000196:embryology*; D009865:Oocytes / Q000166:cytology / Q000502:physiology; D010641:Phenotype; D014176:Protein Biosynthesis; D021382:Protein Sorting Signals / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D011519:Proto-Oncogenes; D014158:Transcription, Genetic; D051153:Wnt Proteins; D051155:Wnt1 Protein; D014981:Xenopus / Q000196:embryology*; D029961:Zebrafish Proteins
D021382:Protein Sorting Signals; D011518:Proto-Oncogene Proteins; D051153:Wnt Proteins; D051155:Wnt1 Protein; D029961:Zebrafish Proteins; D004247:DNA