Nielsen Peter E
Department of Cellular and Molecular Medicine, University of Copenhagen, The Panum Institute, Blegdamsvej 3c, DK-2200, Copenhagen N, Denmark.
Orig Life Evol Biosph. 2007 Oct;37(4-5):323-8. doi: 10.1007/s11084-007-9105-2. Epub 2007 Jul 17.
The possibilities of pseudo peptide DNA mimics like PNA (peptide nucleic acid) having a role for the prebiotic origin of life prior to an RNA world is discussed. In particular a scenario is proposed in which protocells with an achiral genetic material through several generations stepwise is converted into a chiral genetic material, e.g., by incorporation of RNA units. Provided that a sufficiently large sequence space is occupied, a selection process based on catalytic function in which a single cell (first common ancestor) has a definite evolutionary advantage, selection of this cell would by contingency also lock it into homochirality.
本文讨论了类似肽核酸（PNA）的假肽DNA模拟物在RNA世界之前的生命起源前可能发挥的作用。特别提出了一种设想，即具有非手性遗传物质的原始细胞经过几代逐步转化为手性遗传物质，例如通过掺入RNA单元。如果占据了足够大的序列空间，基于催化功能的选择过程中，单个细胞（第一个共同祖先）具有明确的进化优势，那么偶然选择这个细胞也会使其锁定为同手性。
