Ghil J S, Chung H M
Department of Biology Education, Seoul National University, Republic of Korea.
Int J Dev Biol. 1999 Jul;43(4):329-34.
Mesoderm induction is one of the major events of early vertebrate embryonic patterning. It appears to be controlled by sequential and combinatorial actions of several kinds of peptide growth factors. These include activin, fibroblast growth factor (FGF), and transforming growth factor-beta (TGF-beta), among others. In the present study, the function of platelet-derived growth factor (PDGF) in early Xenopus laevis embryogenesis was investigated. In the animal-cap assay, PDGF caused pre-ectodermal tissue to develop a mesoderm specific morphology (elongation) and to express the mesoderm marker genes, MyoD family and alpha-cardiac actin. In addition, two other genes were expressed -related serum response factor SL1 (a dorsal mesodermal marker) and myosin light chain (MLC2-heart marker). A role for PDGF in normal (in vivo) mesoderm induction is implicated because injection of PDGF receptor alpha antisense RNA into 2-cell embryos erased the animal cap's mesoderm marker expression. Those injected embryos also exhibited morphological abnormalities including incomplete gastrulation, failure of neural fold closing, and abnormal somitogenesis.
中胚层诱导是早期脊椎动物胚胎模式形成的主要事件之一。它似乎受几种肽生长因子的顺序和组合作用控制。这些因子包括激活素、成纤维细胞生长因子（FGF）和转化生长因子-β（TGF-β）等。在本研究中，研究了血小板衍生生长因子（PDGF）在非洲爪蟾早期胚胎发生中的功能。在动物帽实验中，PDGF使前外胚层组织发育出中胚层特异性形态（伸长）并表达中胚层标记基因，MyoD家族和α-心肌肌动蛋白。此外，还表达了另外两个基因——与血清反应因子SL1相关的基因（一种背侧中胚层标记物）和肌球蛋白轻链（MLC2——心脏标记物）。PDGF在正常（体内）中胚层诱导中的作用得到了证实，因为将PDGF受体α反义RNA注射到二细胞胚胎中会消除动物帽的中胚层标记物表达。那些注射后的胚胎还表现出形态异常，包括原肠胚形成不完全、神经褶闭合失败和体节发生异常。
