Department of Biomolecular Engineering, Baskin School of Engineering, University of California, Santa Cruz, CA 95060, USA.
Biochimie. 2011 Mar;93(3):556-61. doi: 10.1016/j.biochi.2010.11.012. Epub 2010 Dec 3.
We simulated in our laboratory a prebiotic environment where dry and wet periods were cycled. Under anhydrous conditions, lipid molecules present in the medium could form fluid lamellar matrices and work as organizing agents for the condensation of nucleic acid monomers into polymers. We exposed a mixture of 2'-deoxyribonucleoside 5'-monophosphates and a ssDNA oligomer template to this dry environment at 90 °C under a continuous gentle stream of CO(2) and we followed it with rehydration periods. After five dry/wet cycles we were able to detect the presence of a product that was complementary to the template. The reaction had a 0.5% yield with respect to the template, as measured by staining with the Pico Green(®) fluorescent probe. Absent initial template, the product of the reaction remained below the detection limit. In order to characterize the fidelity of replication, the synthesized strand was ligated to adapters, amplified by PCR, and sequenced. The alignment of the sequenced DNA to the expected complementary sequence revealed that the misincorporation rate was 9.9%. We present these results as a proof of concept for the possibility of having non-enzymatic transfer of sequence information in a prebiotically plausible environment.
我们在实验室中模拟了一个前生物环境，其中循环经历干燥期和湿润期。在无水条件下，存在于介质中的脂质分子可以形成流体层状基质，并作为将核酸单体凝聚成聚合物的组织剂。我们将 2'-脱氧核苷 5'-单磷酸和单链 DNA 寡聚物模板的混合物暴露于 90°C 的干燥环境中，并在持续温和的 CO(2)气流下进行，然后进行复水期。经过五个干湿循环后，我们能够检测到与模板互补的产物。该反应的产率相对于模板为 0.5%，可通过 Pico Green(®)荧光探针染色检测到。在没有初始模板的情况下，反应产物低于检测限。为了表征复制的保真度，将合成的链与接头连接，通过 PCR 扩增，并进行测序。将测序 DNA 与预期的互补序列进行比对，显示错误掺入率为 9.9%。我们将这些结果作为在具有前生物合理性的环境中非酶序列信息转移可能性的概念验证。
