Flores-Alanis Alejandro, Sandner-Miranda Luisa, Delgado Gabriela, Cravioto Alejandro, Morales-Espinosa Rosario
Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico.
BMC Res Notes. 2020 Aug 27;13(1):398. doi: 10.1186/s13104-020-05242-8.
In December 2019 a novel coronavirus (SARS-CoV-2) that is causing the current COVID-19 pandemic was identified in Wuhan, China. Many questions have been raised about its origin and adaptation to humans. In the present work we performed a genetic analysis of the Spike glycoprotein (S) of SARS-CoV-2 and other related coronaviruses (CoVs) isolated from different hosts in order to trace the evolutionary history of this protein and the adaptation of SARS-CoV-2 to humans.
Based on the sequence analysis of the S gene, we suggest that the origin of SARS-CoV-2 is the result of recombination events between bat and pangolin CoVs. The hybrid SARS-CoV-2 ancestor jumped to humans and has been maintained by natural selection. Although the S protein of RaTG13 bat CoV has a high nucleotide identity with the S protein of SARS-CoV-2, the phylogenetic tree and the haplotype network suggest a non-direct parental relationship between these CoVs. Moreover, it is likely that the basic function of the receptor-binding domain (RBD) of S protein was acquired by the SARS-CoV-2 from the MP789 pangolin CoV by recombination and it has been highly conserved.
2019年12月，在中国武汉发现了一种引发当前新冠疫情的新型冠状病毒（SARS-CoV-2）。关于其起源以及对人类的适应性，人们提出了许多问题。在本研究中，我们对SARS-CoV-2以及从不同宿主分离出的其他相关冠状病毒（CoV）的刺突糖蛋白（S）进行了基因分析，以追溯该蛋白的进化史以及SARS-CoV-2对人类的适应性。
基于S基因的序列分析，我们认为SARS-CoV-2的起源是蝙蝠冠状病毒和穿山甲冠状病毒之间重组事件的结果。杂交的SARS-CoV-2祖先跳到了人类身上，并通过自然选择得以维持。尽管蝙蝠冠状病毒RaTG13的S蛋白与SARS-CoV-2的S蛋白具有较高的核苷酸同一性，但系统发育树和单倍型网络表明这些冠状病毒之间不存在直接的亲本关系。此外，S蛋白受体结合域（RBD）的基本功能很可能是SARS-CoV-2通过重组从穿山甲冠状病毒MP789获得的，并且一直高度保守。
