EFGF REGULATES XBRA EXPRESSION DURING XENOPUS GASTRULATION
EFGF REGULATES XBRA EXPRESSION DURING XENOPUS GASTRULATION
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DOI：
10.1002/j.1460-2075.1994.tb06769.x
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发表时间：
1994-10-03
期刊：
影响因子：
11.4
通讯作者：
SLACK, JMW
中科院分区：
文献类型：
--
作者：
ISAACS, HV;POWNALL, ME;SLACK, JMW
我们发现，除了在囊胚阶段中胚层诱导的作用，FGF信号在维持非洲爪蟾原肠胚中胚层的特性中起着重要的作用。eFGF是母源表达的分泌型非洲爪蟾FGF，具有有效的中胚层诱导活性。然而，它在原肠胚形成期间的中胚层中表达最高，表明中胚层诱导期后的作用。eFGF被显性负性FGF受体抑制。过表达显性负性受体的胚胎表现出背中胚层行为的变化，使其在胚孔唇周围移动，而不是在前后方向上伸长。在这样的胚胎中，原肠胚形成期间Xbra表达减少。我们发现，在囊胚阶段，eFGF和Xbra能够激活彼此的表达，这表明它们是自催化调节环的组成部分。此外，我们表明，Xbra表达在分离的原肠胚中胚层细胞维持的eFGF，这表明eFGF继续调节Xbra的表达在囊胚区。此外，在囊胚中期过渡后eFGF的过表达导致原肠胚阶段期间Xbra表达的上调，并导致头的抑制和直肠的扩大，这与FGF显性负性受体表型的后部减少匡威。这些数据表明，eFGF在调节Xbra的表达和在原肠胚阶段控制中胚层细胞行为的eFGF-Xbra调节途径中具有重要作用。
We show that, in addition to a role in mesoderm induction during blastula stages, FGF signalling plays an important role in maintaining the properties of the mesoderm in the gastrula of Xenopus laevis. eFGF is a maternally expressed secreted Xenopus FGF with potent mesoderm-inducing activity. However, it is most highly expressed in the mesoderm during gastrulation, suggesting a role after the period of mesoderm induction. eFGF is inhibited by the dominant negative FGF receptor. Embryos overexpressing the dominant negative receptor show a change of behaviour of the dorsal mesoderm such that it moves around the blastopore lip instead of elongating in an anteroposterior direction. In such embryos there is a reduction in Xbra expression during gastrulation. We show that during blastula stages eFGF and Xbra are able to activate the expression of each other, suggesting that they are components of an autocatalytic regulatory loop. Moreover, we show that Xbra expression in isolated gastrula mesoderm cells is maintained by eFGF, suggesting that eFGF continues to regulate the expression of Xbra in the blastopore region. In addition, overexpression of eFGF after the mid-blastula transition results in the up-regulation of Xbra expression during gastrula stages and causes suppression of the head and enlargement of the proctodeum, which is the converse of the posterior reductions of the FGF dominant negative receptor phenotype. These data suggest an important role for eFGF in regulating the expression of Xbra and for the eFGF-Xbra regulatory pathway in the control of mesodermal cell behaviour during gastrula stages.