Jia Tony Z, Hentrich Christian, Szostak Jack W
Howard Hughes Medical Institute, Department of Molecular Biology, and Center for Computational and Integrative Biology, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA, 02114, USA.
Orig Life Evol Biosph. 2014 Feb;44(1):1-12. doi: 10.1007/s11084-014-9355-8. Epub 2014 Feb 28.
Compartmentalization in a prebiotic setting is an important aspect of early cell formation and is crucial for the development of an artificial protocell system that effectively couples genotype and phenotype. Aqueous two-phase systems (ATPSs) and complex coacervates are phase separation phenomena that lead to the selective partitioning of biomolecules and have recently been proposed as membrane-free protocell models. We show in this study through fluorescence recovery after photobleaching (FRAP) microscopy that despite the ability of such systems to effectively concentrate RNA, there is a high rate of RNA exchange between phases in dextran/polyethylene glycol ATPS and ATP/poly-L-lysine coacervate droplets. In contrast to fatty acid vesicles, these systems would not allow effective segregation and consequent evolution of RNA, thus rendering these systems ineffective as model protocells.
在益生元环境中的区室化是早期细胞形成的一个重要方面，对于有效耦合基因型和表型的人工原细胞系统的发展至关重要。水相两相系统（ATPSs）和复合凝聚层是导致生物分子选择性分配的相分离现象，最近已被提议作为无膜原细胞模型。我们在这项研究中通过光漂白后荧光恢复（FRAP）显微镜显示，尽管此类系统有能力有效浓缩RNA，但在葡聚糖/聚乙二醇ATPS和ATP/聚-L-赖氨酸凝聚层液滴中，RNA在相之间的交换率很高。与脂肪酸囊泡不同，这些系统不允许RNA进行有效分离及随之而来的进化，因此使这些系统作为原细胞模型无效。
