IRCCS E. MEDEA, Bioinformatics, Bosisio Parini, Italy.
University of Milan, Milan, Italy.
Microb Genom. 2023 Jan;9(1). doi: 10.1099/mgen.0.000932.
Archaeovirology efforts provided a rich portrait of the evolutionary history of variola virus (VARV, the cause of smallpox), which was characterized by lineage extinctions and a relatively recent origin of the virus as a human pathogen (~1700 years ago, ya). This contrasts with historical records suggesting the presence of smallpox as early as 3500 ya. By performing an analysis of ancestry components in modern, historic, and ancient genomes, we unveil the progressive drifting of VARV lineages from a common ancestral population and we show that a small proportion of Viking Age ancestry persisted until the 18th century. After the split of the P-I and P-II lineages, the former experienced a severe bottleneck. With respect to the emergence of VARV as a human pathogen, we revise time estimates by accounting for the time-dependent rate phenomenon. We thus estimate that VARV emerged earlier than 3800 ya, supporting its presence in ancient societies, as pockmarked Egyptian mummies suggest.
考古病毒学研究为天花病毒（VARV，引起天花）的进化史提供了丰富的信息，该病毒的进化特征是谱系灭绝和最近才成为人类病原体（约 1700 年前，ya）。这与历史记录中提到的天花早在 3500 年前就存在的说法形成了鲜明对比。通过对现代、历史和古代基因组中的祖先成分进行分析，我们揭示了 VARV 谱系从一个共同祖先群体逐渐漂移的过程，并表明一小部分维京时代的祖先一直延续到 18 世纪。在 P-I 和 P-II 谱系分裂后，前者经历了严重的瓶颈。关于 VARV 作为人类病原体的出现，我们通过考虑时变率现象来修正时间估计。因此，我们估计 VARV 的出现时间早于 3800 年前，这支持了它在古代社会的存在，正如有痘痕的埃及木乃伊所表明的那样。
