Abstract
Despite the widespread occurrence of crystalline inclusions in unicellular eukaryotes, scant attention has been paid to their composition, functions, and evolutionary origins, assuming just their inorganic contents. The advent of Raman microscopy, still scarcely used for biological samples, allowed chemical characterization of cellular inclusions in vivo. Using this method, herein we provide a substantial revision of the cellular crystalline inclusions across the broad diversity of eukaryotes examining all major supergroups. Surprisingly, here we show that 80 % of these crystalline inclusions contain purines, mostly anhydrous guanine (62 %), guanine monohydrate (2 %), uric acid (12 %) and xanthine (4 %). Hence, our findings indicate that purine biocrystallization is a very general and an ancestral eukaryotic process operating by an as-yet-unknown mechanism. Purine crystalline inclusions are high-capacity and rapid-turnover reserves of nitrogen of a great metabolic importance, as well as optically active elements, e.g., present in the light sensing eyespots of flagellates, possessing even more hypothetical functions. Thus, we anticipate our work to be a starting point for more in-depth studies of this phenomenon on the detailed level spanning from cell biology to global ecology, with further potential applications in biotechnologies, bio-optics or in human medicine.
Publisher
Cold Spring Harbor Laboratory
Reference126 articles.
1. Darwin, C . Journal of Researches Into the Geology and Natural History of the Varoius Countries Visited by HMS Beagle, Under the Command of Captain Fitzroy from 1832 to 1836 by Charles Darwin. Colburn (Colburn, 1840).
2. Haeckel, E . Kristallseelen: Studien über das anorganische Leben. (Alfred Kröner Verlag, 1917).
3. Non-skeletal biomineralization by eukaryotes: Matters of moment and gravity;Geomicrobiol. J,2010
4. Purine composition of crystalline cytoplasmic inclusions of Paramecium tetraurelia;Protist,2002
5. Anhydrous β-guanine crystals in a marine dinoflagellate: Structure and suggested function;J. Struct. Biol,2019
Cited by
2 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献