Blair S S
Department of Zoology, University of Wisconsin-Madison 53706.
Dev Biol. 1992 Aug;152(2):263-78. doi: 10.1016/0012-1606(92)90134-3.
The development of supernumerary bristle precursors induced by the mutation shaggy (sgg; also known as zeste-white 3) was examined in the developing wing blade of imaginal and pupal Drosophila. sgg clones were induced by mitotic recombination; clones were marked using enhancer-trap flies which express beta-galactosidase ubiquitously in imaginal tissues, while bristle precursors were identified using sensillum and bristle-specific enhancer-trap lines. It was shown that the precursors of supernumerary sgg bristles in the wing blade mimicked the development of morphologically similar margin bristles, developing in a manner similar to that of anterior sensory bristles in anterior clones and posterior noninnervated bristles in posterior clones. Interestingly, supernumerary anterior sensory bristles appeared outside the normal regions of "proneural" gene activity as identified using anti-achaete. Moreover, sgg could induce the ectopic expression of achaete in anterior clones. Thus, in the anterior wing blade the sgg mutation leads to the formation of ectopic proneural regions.
在成虫和蛹期果蝇发育的翅片中，研究了由突变体“蓬乱”（sgg；也称为小体-白色3）诱导的额外刚毛前体的发育情况。通过有丝分裂重组诱导产生sgg克隆；使用在成虫组织中普遍表达β-半乳糖苷酶的增强子陷阱果蝇标记克隆，同时使用感觉器和刚毛特异性增强子陷阱系鉴定刚毛前体。结果表明，翅片中额外的sgg刚毛前体模仿了形态相似的边缘刚毛的发育过程，其发育方式类似于前部克隆中的前部感觉刚毛和后部克隆中的后部无神经支配刚毛。有趣的是，使用抗无刚毛蛋白鉴定发现，额外的前部感觉刚毛出现在“原神经”基因正常活性区域之外。此外，sgg可诱导前部克隆中无刚毛蛋白的异位表达。因此，在翅片前部，sgg突变导致异位原神经区域的形成。
