XB-ART-24264Biochem Biophys Res Commun 1991 Dec 16;1812:684-90.
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Activin receptor mRNA is expressed early in Xenopus embryogenesis and the level of the expression affects the body axis formation.
Activin is a member of the transforming growth factor beta (TGF-beta) and possesses various activities in cellular control phenomena. During Xenopus embryonic development, activin is thought to act as a natural mesoderm-inducing factor. We isolated here the Xenopus activin receptor cDNA from Xenopus tadpole cDNA library and examined the expression of the Xenopus activin receptor gene during the course of early embryonic development. The Xenopus activin receptor has an 87% homology at the level of deduced amino acid sequence with the mouse activin receptor, and using the cDNA obtained, three bands of mRNA with different lengths were detected in Xenopus embryos throughout early embryogenesis. We synthesized activin receptor mRNA in vitro and tested the effect of the injection of the mRNA into Xenopus fertilized eggs on subsequent development. When the synthetic mRNA was injected into uncleaved fertilized eggs, embryos with reduced trunk structure were formed. However, when the mRNA was injected into the ventral blastomeres at the 16-cell stage, embryos with a secondary body axis were formed. These results indicate the importance of the function of activin receptor in the regulatory mechanism for body axis formation.
PubMed ID: 1661587
Article link: Biochem Biophys Res Commun
Species referenced: Xenopus laevis
Genes referenced: acvr2a
Article Images: [+] show captions
|F~JJ. Nucieotide and deduced amino add sequences of Xenopus a&in receptor. The signalp eptide and transmembraned omaina re indicated by a singleu nderline. The kinase domain is Indicated by arrows. Potential sites for N-linked gfycosylatfon are indicated by double underlines.|
|Fig. 2. Expression of a&in receptor mRNA during earty embryogenesis of Xenopus kevis Ten micrograms of total RNAs extracted from embryos at varlous stages were analyzed by Northern b&t hybridization using the DNA fragment of XAR7 as a probe. Lane 1, oocyte ; lane 2, unfenilired egg ; lane 3, deavage ; lane 4, blastula ; lane 5, gastrula ; lane 6, neurula ; lane 7, tailbud. Arrows Indicate the position of 28s and 18s rlbosomal RNA.|
|Fig. 3. Morphologic comparison between wild-type and activin receptor-mRNA injected embryos. Embryos were injected at fertiliied eggs (6) and 16-cell stage embryos (C) with synthetic XAR7 mRNA (50 pg per embryo) and incubated at 21 C. An uninjected control embryo is shown in (A).|