Jones S D, Ho L, Smith J C, Yordan C, Stiles C D, Mercola M
Dana-Farber Cancer Institute, Boston, Massachusetts.
Dev Genet. 1993;14(3):185-93. doi: 10.1002/dvg.1020140305.
We have cloned the Xenopus PDGF alpha receptor cDNA and have used this clone, along with cDNA encoding PDGF A, to examine their expression pattern in Xenopus embryos and to determine the factors responsible for lineage specificity. Recombinant Xenopus alpha receptor expressed in COS cells exhibits PDGF-A-dependent tyrosine kinase activity. We find that receptor mRNA is present in cultured marginal zone tissue explants and in animal cap tissue induced to form mesoderm either by grafting to vegetal tissue or by treatment with recombinant activin A. In contrast, PDGF A mRNA is expressed in cultured, untreated animal cap tissue and is suppressed by mesoderm induction. These results suggest that ectodermally produced PDGF A may act on the mesoderm during gastrulation and that mesoderm induction establishes the tissue pattern of ligand and receptor expression.
我们克隆了非洲爪蟾血小板衍生生长因子α受体（PDGFα受体）的互补DNA（cDNA），并利用该克隆以及编码血小板衍生生长因子A（PDGF A）的cDNA，来检测它们在非洲爪蟾胚胎中的表达模式，并确定决定谱系特异性的因素。在COS细胞中表达的重组非洲爪蟾α受体表现出依赖于PDGF - A的酪氨酸激酶活性。我们发现，受体信使核糖核酸（mRNA）存在于培养的边缘区组织外植体以及通过移植到植物组织或用重组激活素A处理而诱导形成中胚层的动物帽组织中。相比之下，PDGF A mRNA在未经处理的培养动物帽组织中表达，并在中胚层诱导过程中受到抑制。这些结果表明，外胚层产生的PDGF A可能在原肠胚形成过程中作用于中胚层，并且中胚层诱导建立了配体和受体表达的组织模式。
