Trehalose Renders the Dauer Larva of Caenorhabditis elegans Resistant to Extreme Desiccation
Trehalose Renders the Dauer Larva of Caenorhabditis elegans Resistant to Extreme Desiccation
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DOI：
10.1016/j.cub.2011.06.064
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发表时间：
2011-08-09
期刊：
影响因子：
9.2
通讯作者：
Kurzchalia, Teymuras V.
中科院分区：
文献类型：
--
作者：
Erkut, Cihan;Penkov, Sider;Kurzchalia, Teymuras V.
水对地球上的生命至关重要。然而，如果没有它，一些生物体可能会中断其生命周期并暂时进入无代谢状态，称为脱水共生[1]。据推测，糖（特别是海藻糖）有助于在脱水条件下的生存[2]。然而，海藻糖的作用仍然不清楚，因为相应的证据是完全相关的，并且主要基于体外研究，没有对海藻糖代谢进行任何遗传操作。在这项研究中，我们使用C。线虫作为遗传模型，研究脱水生活的分子机制。结果表明，C.秀丽隐杆线虫幼虫是一种真正的无水生物：在特定条件下，即使失去98%的身体水分，它也能存活。这种能力与海藻糖量的数倍增加相关。不能合成海藻糖的突变体甚至不能在轻度脱水下存活。光镜和电镜观察表明，海藻糖的主要功能之一是保护膜组织。傅立叶变换红外光谱的整个蠕虫表明，这是通过保持均匀和紧凑的包装脂酰基链。通过红外光谱，我们现在可以区分“干燥，但活着”的幼虫和“干燥和死亡”的幼虫。
Water is essential for life on Earth. In its absence, however, some organisms can interrupt their life cycle and temporarily enter an ametabolic state, known as anhydrobiosis [1]. It is assumed that sugars (in particular trehalose) are instrumental for survival under anhydrobiotic conditions [2]. However, the role of trehalose remained obscure because the corresponding evidence was purely correlative and based mostly on in vitro studies without any genetic manipulations of trehalose metabolism. In this study, we used C. elegans as a genetic model to investigate molecular mechanisms of anhydrobiosis. We show that the C. elegans dauer larva is a true anhydrobiote: under defined conditions it can survive even after losing 98% of its body water. This ability is correlated with a several fold increase in the amount of trehalose. Mutants unable to synthesize trehalose cannot survive even mild dehydration. Light and electron microscopy indicate that one of the major functions of trehalose is the preservation of membrane organization. Fourier-transform infrared spectroscopy of whole worms suggests that this is achieved by preserving homogeneous and compact packing of lipid acyl chains. By means of infrared spectroscopy, we can now distinguish a "dry, yet alive" larva from a "dry and dead" one.