Autonomous neural axis formation by ectopic expression of the protooncogene c-ski.
The ski oncogene was originally isolated as an avian retroviral gene with the ability to induce quail embryonic cells to differentiate into muscle. Mice containing a chicken c-ski transgene exhibit postnatal hypertrophy of skeletal muscle. Xenopus ski (Xski) protein is maternal and present throughout early development. We show that overexpression of Xski RNA in Xenopus embryos results in the cell-autonomous induction of secondary neural axis formation. Injection of Xski RNA into prospective endodermal cells resulted in the formation of an ectopic neural tube-like structure and cells derived from the injected blastomeres populated the spinal cord. Injected Xski RNA was able to induce neural-specific gene expression directly in ectodermal explants in the absence of the expression of mesodermal markers. The widespread distribution of ski protein in the early gastrula embryo including the dorsal animal region supports a role for ski in neural axis formation in vivo.
Amaravadi
L S
LS
Lilly Research Laboratories, Division of Eli Lilly and Company, Greenfield, Indiana 46140, USA.
Neff
A W
AW
Sleeman
J P
JP
Smith
R C
RC
D000595:Amino Acid Sequence; D000818:Animals; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D004475:Ectoderm / Q000502:physiology; D004527:Egg Proteins / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000502:physiology / Q000648:ultrastructure; D004707:Endoderm / Q000166:cytology / Q000502:physiology; D005775:Gastrula / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D008969:Molecular Sequence Data; D009420:Nervous System / Q000196:embryology*; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D015398:Signal Transduction; D014982:Xenopus laevis / Q000196:embryology
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D004527:Egg Proteins; D011518:Proto-Oncogene Proteins