Nature, Source and Function of Pigments in Tardigrades: In Vivo Raman Imaging of Carotenoids in Echiniscus blumi
Nature, Source and Function of Pigments in Tardigrades: In Vivo Raman Imaging of Carotenoids in Echiniscus blumi
复制标题
DOI：
10.1371/journal.pone.0050162
复制
发表时间：
2012-11-21
期刊：
影响因子：
3.7
通讯作者：
Rebecchi, Lorena
中科院分区：
文献类型：
--
作者：
Bonifacio, Alois;Guidetti, Roberto;Rebecchi, Lorena
水熊虫是一种微小的水生动物，具有非凡的能力来承受恶劣的物理条件，如脱水或暴露于有害的高能辐射。负责这种鲁棒性的机制目前知之甚少，但对氧化应激的保护被认为发挥了作用。尽管事实上，许多缓步动物物种是不同的色素，稀缺的信息是关于这一特点。通过对活体标本的拉曼显微光谱分析，鉴定了缓步动物Echiniscus blumi中的色素为类胡萝卜素，并观察了它们在动物体内的分布。证明了这些色素的饮食来源，以及它们存在于这些动物的卵和眼斑中，以及它们不存在于动物的外层（即，角质层和表皮）。使用体内半定量拉曼显微光谱，减少类胡萝卜素含量后，诱导氧化应激检测，表明这种方法可用于研究类胡萝卜素在氧化应激相关过程中的作用，在缓步动物。因此，这种方法可以用于进一步的调查，以测试几个假设有关的功能，这些类胡萝卜素在缓步动物作为光保护色素对电离辐射或作为抗氧化剂防御这些生物体对氧化应激过程中发生的干燥过程。
Tardigrades are microscopic aquatic animals with remarkable abilities to withstand harsh physical conditions such as dehydration or exposure to harmful highly energetic radiation. The mechanisms responsible for such robustness are presently little known, but protection against oxidative stresses is thought to play a role. Despite the fact that many tardigrade species are variously pigmented, scarce information is available about this characteristic. By applying Raman micro-spectroscopy on living specimens, pigments in the tardigrade Echiniscus blumi are identified as carotenoids, and their distribution within the animal body is visualized. The dietary origin of these pigments is demonstrated, as well as their presence in the eggs and in eye-spots of these animals, together with their absence in the outer layer of the animal (i.e., cuticle and epidermis). Using in-vivo semi-quantitative Raman micro-spectroscopy, a decrease in carotenoid content is detected after inducing oxidative stress, demonstrating that this approach can be used for studying the role of carotenoids in oxidative stress-related processes in tardigrades. This approach could be thus used in further investigations to test several hypotheses concerning the function of these carotenoids in tardigrades as photo-protective pigments against ionizing radiations or as antioxidants defending these organisms against the oxidative stress occurring during desiccation processes.