Northrop J L, Kimelman D
Department of Biochemistry, School of Medicine, University of Washington, Seattle 98195.
Dev Biol. 1994 Feb;161(2):490-503. doi: 10.1006/dbio.1994.1047.
We have identified a dorsal-ventral difference in the specification of mesoderm in vivo by examining the effect of the dominant-negative FGF receptor on a new member of the Xenopus caudal gene family, Xcad-3. Xcad-3 is expressed throughout the marginal zone during the gastrula stages and serves as a useful marker for events occurring within the mesoderm. Disruption of the FGF signaling pathway by the dominant-negative FGF receptor, disrupts the Xcad-3 expression pattern, eliminating expression preferentially from the dorsal regions of the embryo. We also find that the expression of the Xenopus brachyury homolog, Xbra, is more readily eliminated from the dorsal than the ventral region of the embryo by the dominant-negative FGF receptor, indicating that the observed dorsal-ventral differences are not unique to Xcad-3. These results demonstrate the importance of regional effects on FGF-mediated induction in vivo and suggest that FGF-dependent expression of mesodermal genes depends upon the localization of other factors which establish dorsal-ventral differences within the embryo.
通过检测显性负性成纤维细胞生长因子（FGF）受体对非洲爪蟾尾部基因家族新成员Xcad - 3的影响，我们已经确定了中胚层在体内特化过程中的背腹差异。在原肠胚阶段，Xcad - 3在整个边缘区表达，并作为中胚层内发生事件的一个有用标记。显性负性FGF受体破坏FGF信号通路，会破坏Xcad - 3的表达模式，优先消除胚胎背侧区域的表达。我们还发现，显性负性FGF受体更容易消除胚胎背侧而非腹侧区域的非洲爪蟾短尾同源物Xbra的表达，这表明观察到的背腹差异并非Xcad - 3所特有。这些结果证明了区域效应在体内FGF介导的诱导中的重要性，并表明中胚层基因的FGF依赖性表达取决于胚胎内建立背腹差异的其他因子的定位。
