Mechanical Control of Whole Body Shape by a Single Cuticular Protein Obstructor-E in Drosophila melanogaster.
Mechanical Control of Whole Body Shape by a Single Cuticular Protein Obstructor-E in Drosophila melanogaster.
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DOI：
10.1371/journal.pgen.1006548
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发表时间：
2017-01
期刊：
影响因子：
4.5
通讯作者：
Kojima T
中科院分区：
文献类型：
--
作者：
Tajiri R;Ogawa N;Fujiwara H;Kojima T
身体形状比身体计划更多变。一种独立于身体平面图改变身体形状的方法是使身体机械变形。身体形状在多大程度上受到物理调节，或者参与形态发生物理控制的分子，仍然是难以捉摸的。在果蝇变态过程中，覆盖幼虫身体的角质层（外骨骼）纵向收缩，横向膨胀，成为椭圆形的蛹壳（蛹）。在这里，我们表明，果蝇Obstructor-E（Obst-E）是一种蛋白质成分的幼虫角质层，赋予定向收缩/扩张。在缺乏obst-E功能的情况下，幼虫的角质层不能发生变形，最终变成树枝状的蛹。我们目前的研究结果表明，Obst-E调节甲壳素，长链多糖和昆虫角质层的中心组成部分的安排，并指导幼虫角质层上的超细胞脊的形成。我们进一步表明，OBST-E是本地所需的定向形状变化的角质层在变态过程中，这是与这些脊的形态变化。因此，Obst-E通过控制外骨骼的机械性能以直接的物理方式显著影响体形。物体的运动，无论是有生命的还是没有生命的，都应该取决于它们的物质属性和作用在它们上面的力。创造多细胞生物体整体形状的机械过程，或调节这些过程的基因，在很大程度上是未知的。昆虫体表有角质层，角质层是由蛋白质和多糖甲壳素组成的基质。我们发现，在变态的果蝇果蝇，角质层覆盖的长而薄的幼虫（蛆）经历纵向收缩和横向扩张，成为短而粗壮的蛹覆盖蛹。此外，我们确定了一个单一的蛋白质成分的幼虫角质层，赋予定向收缩性/膨胀性，从而确定蛹的身体形状在机械的方式。
Body shapes are much more variable than body plans. One way to alter body shapes independently of body plans would be to mechanically deform bodies. To what extent body shapes are regulated physically, or molecules involved in physical control of morphogenesis, remain elusive. During fly metamorphosis, the cuticle (exoskeleton) covering the larval body contracts longitudinally and expands laterally to become the ellipsoidal pupal case (puparium). Here we show that Drosophila melanogaster Obstructor-E (Obst-E) is a protein constituent of the larval cuticle that confers the oriented contractility/expandability. In the absence of obst-E function, the larval cuticle fails to undergo metamorphic shape change and finally becomes a twiggy puparium. We present results indicating that Obst-E regulates the arrangement of chitin, a long-chain polysaccharide and a central component of the insect cuticle, and directs the formation of supracellular ridges on the larval cuticle. We further show that Obst-E is locally required for the oriented shape change of the cuticle during metamorphosis, which is associated with changes in the morphology of those ridges. Thus, Obst-E dramatically affects the body shape in a direct, physical manner by controlling the mechanical property of the exoskeleton. Shapes of objects, living or not, should depend on their material properties and forces acting on them. Mechanical processes that create whole body shapes of multicellular organisms, or genes that regulate such processes, are largely unknown. Insect bodies are coated by cuticle, a matrix composed of proteins and the polysaccharide chitin. We show that, during metamorphosis of the fruit fly Drosophila melanogaster, the cuticle covering the long and thin larva (maggot) undergoes longitudinal contraction and lateral expansion to become the short and stout puparium covering the pupa. Furthermore, we identify a single protein component of the larval cuticle that confers the oriented contractility/expandability, thereby determining the pupal body shape in a mechanical manner.