nature, source and function of pigments in tardigrades in vivo raman imaging of carotenoids in echiniscus blumi色素的性质、来源和作用缓步类体内的类胡萝卜素拉曼成像echiniscus blumi.pdfVIP

Nature, Source and Function of Pigments in Tardigrades: In Vivo Raman Imaging of Carotenoids in Echiniscus blumi 1 2 3 1 2 Alois Bonifacio *, Roberto Guidetti , Tiziana Altiero , Valter Sergo , Lorena Rebecchi 1 Centre of Excellence for Nanostructured Materials and Department of Engineering and Architecture, University of Trieste, Trieste, Italy, 2 Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy, 3 Department of Education and Human Sciences, University of Modena and Reggio Emilia, Reggio Emilia, Italy Abstract 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