Parks A L, Muskavitch M A
Department of Biology, Indiana University, Bloomington 47405.
Dev Biol. 1993 Jun;157(2):484-96. doi: 10.1006/dbio.1993.1151.
Analyses of Delta (Dl) temperature-sensitive mutants reveal that reductions in Dl function during metamorphosis of Drosophila melanogaster can lead to multiplication or loss of bristle organs on the adult notum, depending on the developmental interval during which such mutants are pulsed at restrictive temperature. Site-dependent macrochaeta multiplication or loss results from pulses 0-21 hr after puparium formation (APF). Microchaeta multiplication results from pulses 7-30 hr APF, while microchaeta loss results from pulses 24-47 hr APF. Supernumerary bristle organs that develop in Dl mutants consist of the normal complement of trichogen, tormogen, neuron, and thecogen cells, and appear to arise due to the specification of super-numerary bristle first-order precursor (pI) cells within proneural groups in the developing notum. Loss of complete bristle organs in Dl mutants is correlated with the differentiation of all four progeny of the pI cell into neurons. We conclude that Dl function is required for cellular interactions central to the correct specification of pI cells within proneural groups, as well as for morphogenesis of the bristle organ itself.
对Delta（Dl）温度敏感突变体的分析表明，在黑腹果蝇变态发育过程中，Dl功能的降低会导致成虫背板上刚毛器官的增殖或缺失，这取决于此类突变体在限制温度下进行脉冲处理的发育阶段。蛹形成后（APF）0至21小时的脉冲会导致位点依赖性的大刚毛增殖或缺失。小刚毛增殖是由APF 7至30小时的脉冲引起的，而小刚毛缺失则是由APF 24至47小时的脉冲导致的。在Dl突变体中发育出的多余刚毛器官由毛原细胞、膜原细胞、神经元和皮细胞的正常组合构成，并且似乎是由于发育中的背板原神经簇内多余刚毛一级前体（pI）细胞的特化而产生的。Dl突变体中完整刚毛器官的缺失与pI细胞的所有四个子代分化为神经元有关。我们得出结论，Dl功能对于原神经簇内pI细胞正确特化所必需的细胞间相互作用以及刚毛器官本身的形态发生都是必需的。
