Li X, Gutjahr T, Noll M
Institute for Molecular Biology II, University of Zürich, Switzerland.
EMBO J. 1993 Apr;12(4):1427-36. doi: 10.1002/j.1460-2075.1993.tb05786.x.
During Drosophila embryogenesis, position along the anteroposterior axis is specified within each segment by the products of the segment-polarity genes which include wingless (wg) and gooseberry (gsb). The striped expression of these genes in each segment is initially established by the pair-rule gene products during late blastoderm. This pattern is subsequently maintained after germ band extension by interaction among the segment-polarity genes themselves. Here we show that the maintenance of gsb, a PHox gene encoding a paired-domain and a homeodomain, is controlled by the wg signal, the homolog of the murine Wnt-1 protein. A control element responsible for wg-dependent maintenance of gsb expression, gsb-late element, is separable from an element required for the initial activation of gsb by pair-rule transcription factors, gsb-early element. The significance of such a regulatory strategy is discussed with respect to the establishment and maintenance of cell states within each segment by segment-polarity genes.
在果蝇胚胎发育过程中，前后轴上的位置在每个体节内由体节极性基因的产物来确定，这些基因包括无翅基因（wg）和醋栗基因（gsb）。这些基因在每个体节中的条纹状表达最初是在胚盘后期由成对规则基因的产物建立的。在胚带延伸后，这种模式通过体节极性基因自身之间的相互作用得以维持。在这里，我们表明，gsb是一个编码配对结构域和同源结构域的PHox基因，其维持受wg信号（小鼠Wnt-1蛋白的同源物）的控制。负责wg依赖性维持gsb表达的控制元件gsb晚期元件，与成对规则转录因子最初激活gsb所需的元件gsb早期元件是可分离的。关于体节极性基因在每个体节内细胞状态的建立和维持，讨论了这种调控策略的意义。
