Cell shape and interaction defects in alpha-spectrin mutants of Drosophila melanogaster.
Cell shape and interaction defects in alpha-spectrin mutants of Drosophila melanogaster.
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DOI：
10.1083/jcb.123.6.1797
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发表时间：
1993-12
期刊：
影响因子：
--
通讯作者：
Branton D
中科院分区：
文献类型：
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作者：
Lee JK;Coyne RS;Dubreuil RR;Goldstein LS;Branton D
我们表明，α-血影蛋白基因是必不可少的幼虫的生存和发展的特点在果蝇的几个α-血影蛋白突变。使用P-元件小基因拯救和序列分析来鉴定α-血影蛋白基因作为3号染色体的Dras-Roughened-ecdysoneless区的l（3）dre 3互补组（Sliter等人，1988年）。携带α-血影蛋白cDNA（其表达由泛素启动子驱动）的种系转化体完全拯救了l（3）dre 3等位基因的第一至第二龄致死特性。在两个γ射线诱导的等位基因的分子缺陷进行了鉴定。其中一个突变导致二龄幼虫致死，在α-血影蛋白片段22（从氨基酸残基2312开始）中含有73-bp缺失，在该片段中发现的两个EF手之间产生提前终止密码子。第二个突变导致一龄幼虫致死，在片段1的中间（在氨基酸残基92处）含有20个碱基对缺失，导致提前终止密码子。血影蛋白缺乏的幼虫的检查揭示了肠道上皮细胞之间的接触损失和细胞-基质相互作用的破坏。最显著的形态学变化见于复杂细胞结构的组织中，如中肠，其中杯状嗜铜细胞与相邻间质细胞之间的细胞接触丧失，并伴有嗜铜细胞刷状缘的解体。我们的血影蛋白缺陷的幼虫的检查表明，非红细胞血影蛋白的一个重要作用是稳定细胞与细胞的相互作用，这是至关重要的维持细胞的形状和组织内的亚细胞组织。
We show that the alpha-spectrin gene is essential for larval survival and development by characterizing several alpha-spectrin mutations in Drosophila. P-element minigene rescue and sequence analysis were used to identify the alpha-spectrin gene as the l(3)dre3 complementation group of the Dras-Roughened-ecdysoneless region of chromosome 3 (Sliter et al., 1988). Germ line transformants carrying an alpha-spectrin cDNA, whose expression is driven by the ubiquitin promoter, fully rescued the first to second instar lethality characteristic of the l(3)dre3 alleles. The molecular defects in two gamma-ray-induced alleles were identified. One of these mutations, which resulted in second instar lethality, contained a 73-bp deletion in alpha-spectrin segment 22 (starting at amino acid residue 2312), producing a premature stop codon between the two EF hands found in this segment. The second mutation, which resulted in first instar lethality, contained a 20 base pair deletion in the middle of segment 1 (at amino acid residue 92), resulting in a premature stop codon. Examination of the spectrin- deficient larvae revealed a loss of contact between epithelial cells of the gut and disruption of cell-substratum interactions. The most pronounced morphological change was seen in tissues of complex cellular architecture such as the middle midgut where a loss of cell contact between cup-shaped cuprophilic cells and neighboring interstitial cells was accompanied by disorganization of the cuprophilic cell brush borders. Our examination of spectrin deficient larvae suggests that an important role of non-erythroid spectrin is to stabilize cell to cell interactions that are critical for the maintenance of cell shape and subcellular organization within tissues.