Bejsovec A, Martinez Arias A
Department of Zoology, University of Cambridge, UK.
Development. 1991 Oct;113(2):471-85. doi: 10.1242/dev.113.2.471.
The larval epidermis of Drosophila shows a stereotyped segmentally repeating pattern of cuticular structures. Mutants deficient for the wingless gene product show highly disrupted patterning of the larval cuticle. We have manipulated expression of the wg gene product to assess its role in this patterning process. We present evidence for four distinct phases of wg function in epidermal cells: (1) an early requirement in engrailed-expressing cells to establish and maintain stable expression of en, (2) a discrete period when wg and en gene products act in concert to generate positional values in the anterior portion of the ventral segment and all values of the dorsal and lateral epidermis, (3) a progressive function (dependent on prior interaction with the en-expressing cells) in conferring positional values to cells within the posterior portion of the segment, and (4) a late continuous requirement for maintaining some ventral positional values.
果蝇幼虫表皮呈现出角质层结构的定型节段重复模式。缺乏无翅基因产物的突变体表现出幼虫角质层高度紊乱的模式。我们通过操纵wg基因产物的表达来评估其在这一模式形成过程中的作用。我们提供了证据表明wg在表皮细胞中的功能有四个不同阶段：（1）在表达 engrailed 的细胞中对建立和维持 en 的稳定表达有早期需求；（2）一个离散时期，此时wg和en基因产物协同作用，在腹节前部以及背侧和外侧表皮的所有区域产生位置值；（3）一种渐进功能（依赖于先前与表达 en 的细胞的相互作用），赋予节段后部细胞位置值；（4）对维持一些腹侧位置值有后期持续需求。
