Noordermeer J, Johnston P, Rijsewijk F, Nusse R, Lawrence P A
Howard Hughes Medical Institute, Stanford University, California 94305-5428.
Development. 1992 Nov;116(3):711-9. doi: 10.1242/dev.116.3.711.
The segment polarity gene wingless has an essential function in cell-to-cell communication during various stages of Drosophila development. The wingless gene encodes a secreted protein that affects gene expression in surrounding cells but does not spread far from the cells where it is made. In larvae, wingless is necessary to generate naked cuticle in a restricted part of each segment. To test whether the local accumulation of wingless is essential for its function, we made transgenic flies that express wingless under the control of a hsp70 promoter (HS-wg flies). Uniform wingless expression results in a complete naked cuticle, uniform armadillo accumulation and broadening of the engrailed domain. The expression patterns of patched, cubitus interruptus Dominant and Ultrabithorax follow the change in engrailed. The phenotype of heatshocked HS-wg embryos resembles the segment polarity mutant naked, suggesting that embryos that overexpress wingless or lack the naked gene enter similar developmental pathways. The ubiquitous effects of ectopic wingless expression may indicate that most cells in the embryo can receive and interpret the wingless signal. For the development of the wild-type pattern, it is required that wingless is expressed in a subset of these cells.
节段极性基因无翅在果蝇发育的各个阶段的细胞间通讯中具有重要功能。无翅基因编码一种分泌蛋白，它会影响周围细胞的基因表达，但不会从其产生的细胞扩散太远。在幼虫中，无翅对于在每个节段的特定部位生成裸表皮是必需的。为了测试无翅的局部积累对其功能是否至关重要，我们制作了在热休克蛋白70启动子（HS-wg果蝇）控制下表达无翅的转基因果蝇。均匀的无翅表达导致完全的裸表皮、均匀的犰狳积累以及engrailed结构域的扩展。patched、间断翅脉显性和超双胸的表达模式跟随engrailed的变化。热休克处理的HS-wg胚胎的表型类似于节段极性突变体裸，这表明过度表达无翅或缺乏裸基因的胚胎进入相似的发育途径。异位无翅表达的普遍效应可能表明胚胎中的大多数细胞能够接收并解读无翅信号。对于野生型模式的发育，需要无翅在这些细胞的一个子集中表达。
