Yokouchi Y, Sasaki H, Kuroiwa A
Biological Institute, Faculty of Science, Tohoku University, Sendai, Japan.
Nature. 1991 Oct 3;353(6343):443-5. doi: 10.1038/353443a0.
The complex architecture of the limb cartilage pattern probably develops by the sequential segmentation and branching process of precartilaginous cell condensation under the control of positional signalling provided by the zone of polarizing activity (anteroposterior) and the apical ectodermal ridge (proximodistal). This signalling is monitored and interpreted in the mesenchymal cells and induces the position-specific response of subsets of genes. Homeobox genes may be responsible for the interpretation of signalling. A correlation between limb pattern and expression domains of the homeobox genes in the upstream region of Hox/Chox-4 has been proposed. We have analysed the spatial expression pattern of the Chox-1 genes during development of chick limb buds. In contrast to genes in Hox/Chox-4 expressed coordinately along the anteroposterior axis, homeobox genes in Chox-1 have unique and mutually exclusive expression domains along the proximodistal axis. We report here that the expression domains of the Chox-1 genes are closely related to the segmental structure of cartilage along the proximodistal axis, whereas the expression domains of the Chox-4 genes are related to the cartilage branching pattern.
肢体软骨模式的复杂结构可能是在由极化活性区（前后轴）和顶端外胚层嵴（近远轴）提供的位置信号控制下，通过软骨前体细胞凝聚的顺序性分割和分支过程形成的。这种信号在间充质细胞中被监测和解读，并诱导基因亚群的位置特异性反应。同源框基因可能负责信号的解读。有人提出肢体模式与Hox/Chox - 4上游区域同源框基因的表达域之间存在相关性。我们分析了鸡胚肢体芽发育过程中Chox - 1基因的空间表达模式。与沿前后轴协同表达的Hox/Chox - 4基因不同，Chox - 1中的同源框基因沿近远轴具有独特且相互排斥的表达域。我们在此报告，Chox - 1基因的表达域与沿近远轴的软骨节段结构密切相关，而Chox - 4基因的表达域与软骨分支模式相关。
