Crossley P H, Martinez S, Martin G R
Department of Anatomy, School of Medicine, University of California at San Francisco, 94143-0452, USA.
Nature. 1996 Mar 7;380(6569):66-8. doi: 10.1038/380066a0.
Vertebrate midbrain development depends on an organizing centre located at the isthmus, a constriction in the embryonic mid/hindbrain region. Isthmic tissue grafts transform chick caudal forebrain into an ectopic midbrain that is the mirror image of the normal midbrain. Here we report that FGF8 protein has the same midbrain-inducing and polarizing effect as isthmic tissue. Moreover, FGF8 induces ectopic expression in the forebrain of genes normally expressed in the isthmus, suggesting that the ectopic midbrain forms under the influence of signals from a new 'isthmus-like' organizing centre induced in the forebrain. Because Fgf8 itself is expressed in the isthmus, our results identify FGF8 as an important signalling molecule in normal midbrain development.
脊椎动物中脑的发育依赖于位于峡部的一个组织中心，峡部是胚胎中脑/后脑区域的一个收缩部位。峡部组织移植可将鸡的尾侧前脑转化为一个异位中脑，该异位中脑是正常中脑的镜像。我们在此报告，FGF8蛋白具有与峡部组织相同的中脑诱导和极化作用。此外，FGF8可诱导前脑中正常在峡部表达的基因的异位表达，这表明异位中脑是在前脑诱导产生的新的“类峡部”组织中心发出的信号影响下形成的。由于Fgf8本身在峡部表达，我们的结果确定FGF8是正常中脑发育中的一个重要信号分子。
