日本新冠病例数持续下降，是因病毒要自我灭绝了？
“修复德尔塔毒株基因组变异的酶发生了变化，新冠病毒可能是来不及修复就死亡了。“
近日，日本国立遗传学研究所和新潟大学的团队在日本人类遗传学会上公布的一项研究传递出上述信息。
日本在8月病例数达到峰值后，病例数便开始骤减，日增病例数从2.5万一路降至目前的200例左右。
研究者发现，日本8月下旬的疫情高峰前，几乎所有的新冠病毒都已置换为酶发生变化的类型。该种酶为“nsp14”，“nsp14”具有核糖核酸外切酶和N7甲基转移酶的活性，是病毒复制不可或缺的蛋白质。日本新冠病毒中“nsp14”发生变异之后，导致基因组不断累积错误突变，最终因为来不及修复而导致病毒自我灭绝。
研究者对日本国立感染症研究所公开的、日本国内检测出的新冠基因组数据进行了分析，结果发现，在第五波疫情中，nsp14相关基因变化的病毒比例随着感染蔓延而增加，从高峰前到平息前几乎占了感染者的全部。
如果nsp14的出现导致了日本新冠疫情的缓解，对于新冠药物的发现也是一个突破。一位药物研究专家对第一财经表示，“从历史上看，所有的非结构蛋白，一直是可行的药物靶点。”
目前新冠病毒（COVID-19）潜在靶标分为非结构蛋白与结构蛋白两大类。作为非结构蛋白的nsp14，如果能阻断新冠病毒的复制，那么新冠药物的研发又有了一个新的机会。
英文报道
The number of confirmed diagnoses in Japan has dropped sharply, and the study finds that the new coronavirus dies after a new mutation-IT & Health
https://www.breakinglatest.news/news/the-number-of-confirmed-diagnoses-in-japan-has-dropped-sharply-and-the-study-finds-that-the-new-coronavirus-dies-after-a-new-mutation-it-health/
Entering October, the number of confirmed cases of the new crown in Japan unexpectedly began to drop sharply. Japan’s epidemic prevention and control measures are not stronger than before, but are relaxing. This abnormal phenomenon is likely to be related to the mutation of the virus. Japanese researchers found The new mutation of the new coronavirus may cause the virus to self-death.
According to a report from Kyodo News on the 31st, the research team from Japan’s National Institute of Genetics and Niigata University recently published the latest research. Studies have found that in the genome of the delta mutant strain, an enzyme called “nsp14” has mutated, causing the virus to fail to complete repair in time, leading to the virus’s self-extinction.
In the process of rapid virus replication and spread, the genome sometimes undergoes wrong mutations, which is also one of the main causes of disease.
At this time, “nsp14” is generally responsible for repairing. However, if the repair is not timely and too many mutations are accumulated, the virus may not be able to reproduce.
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In addition, the research team speculated that an enzyme called “APOBEC” changed “nsp14”. It is said that in East Asia and Oceania, this enzyme is particularly active in many people.
（注：这句黑体字对理解本次疫情的流行很重要）
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发表的有关研究论文
这篇讨论以夷制夷：
https://pubmed.ncbi.nlm.nih.gov/34673601/
该基因作用机理研究：
https://pubs.rsc.org/en/content/articlehtml/2021/cb/d1cb00135c
https://www.sciencedirect.com/science/article/pii/S0021925821010218
https://mdpi-res.com/d_attachment/life/life-11-01129/article_deploy/life-11-01129.pdf
该基因还有其它作用：
https://animaldiseases.biomedcentral.com/articles/10.1186/s44149-021-00025-5
想起一句老话：欲使之灭亡，必先使之疯狂
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