2020-06-14 07:32
Is this the mutation that made coronavirus spread like wildfire in NYC and Italy? Super-infectious strain has four-times as many 'spikes' that let it invade human cells compared to milder forms seen in California
这就是让冠状病毒在纽约和意大利像野火一样蔓延的变异吗?与加州看到的较温和的形式相比，超级传染性菌株具有四倍于加州较温和形式的“尖峰”，使其能够入侵人类细胞
A minute mutation to the strain of coronavirus that's spread in the US and Italy have made it far more infectious than other variants of the virus are, a new study suggests.
一项新的研究表明， 对在美国和意大利传播的冠状病毒株进行了微小的突变，使其比其他变种的病毒具有更强的传染性。
The potent version of SARS-CoV-2 has four to five times more 'spikes' that allow it to latch onto human cells on its surface.
强大版本的SARS-CoV-2有四到五倍多的“尖刺”，使其能够附着在其表面的人类细胞上。
Not only does this trait make it more infectious,but it also makes the virus more stable and resilient.
这一特征不仅使它更具传染性，而且还使病毒更稳定、更具弹性。
Since coronavirus became a pandemic, scientists have puzzled over why it has seemed to decimate some states and countries, while both its spread and lethality hae been limited.
自从冠状病毒成为- -种大流行以来，科学家们一直在困惑，为什么它似乎摧毁了一些州和国家，而它的传播和致命性都受到了限制。
Previous research had suggested a seemingly more potent strain that hit Italy and Europe and spread to New York City, which swiftly became the epicenter of the pandemic.
之前的研究表明，一种似乎更有效的毒株袭击了意大利和欧洲，并蔓延到纽约市，纽约市迅速成为大流行的中心。
Now, scientists at Scripps Research believe they've confirmed that theory, and identified the mutation that super-charged the particularly infectious variant of coronavirus.
现在，斯克里普斯研究公司的科学家们相信他们已经证实了这一理论，并确定了使这种传染性特别强的冠状病毒变种增压的突变。
Researchers there isolated various strains of coronavirus that have been identified by their genetic signatures around the world.
那里的研究人员分离出了各种冠状病毒株，这些病毒株已经通过它们在世界各地的基因特征进行了鉴定。
They then put each into a sort microscopic cage match, testing how aggressively the respective strains attacked human cells in petri dishes.
然后，他们将每个菌株放入一种类似于显微笼子的匹配中，测试各自的菌株攻击培养皿中的人类细胞的攻击性有多强。
One strain was the clear winner - the iteration of the virus with the mutated gene that gave it more 'spike' proteins.
--种菌株是明显的赢家_病毒与突变基因的迭代，这给了它更多的“尖峰”蛋白。
'Viruses with this mutation were much more infectious than those without the mutation in the cell culture system we used,' said virologist Dr Hyeryun Choe, PhD, senior author of the study.
该研究的资深作者、病毒学家Hyeryun Choe博士说:“在我们使用的细胞培养系统中，带有这种突变的病毒比没有突变的病毒具有更强的传染性。”
The 'spike' is a protein on the surface of the coronavirus - known as SARS-CoV-2 - that allows it to latch onto receptors on human cells'surfaces.
“尖峰”是冠状病毒(称为SARS-CoV-2)表面的- -种蛋白质，它使其能够附着在人类细胞表面的受体上。
Specifically, it binds to ACE2 receptors, which are prevalent on the surface of lung cells as well as blood vessels - making these systems prime targets for coronavirus.
具体地说，它与ACE2受体结合，ACE2受体普遍存在于肺细胞和血管表面，使这些系统成为冠状病毒的主要靶点。
The more spikes it has, the more opportunities the virus has to stick to a human cell, and hijack its machinery to make more of itself.
它的尖峰越多，病毒就有越多的机会粘在人类细胞上，劫持它的机器来制造更多的自己。
And the mutant strain that's spread in the US and Italy has them in spades.
而在美国和意大利传播的突变菌株则确凿地证明了这一点。
'The number - or density - of functional spikes on the virus is 4 or 5 times greater due to this mutation,' said Dr Choe.
Choe博士说:“由于这种变异，病毒.上的功能性尖峰的数量或密度增加了4到5倍。”
Not only did it have more spikes, it had particularly well-adapted ones.
它不仅有更多的尖峰，还有特别适应的尖峰。
Its protein spike was flexible rather than rigid.That gives it the same advantage that modern suspensions bridges have. Swaying and jostling might bend it - but it won't break.
它的蛋白质峰是柔性的，而不是刚性的。这给了它与现代吊桥相同的优势。摇摆和推挤可能会把它弄弯，但它不会折断。
And the longer and more stabley it can hang onto receptors, the better the opportunity for viral particles to march into the human cell and take it over, without the virus falling to pieces.
而且它在受体上附着的时间越长，越稳定，病毒颗粒进入人类细胞并接管它的机会就越大，而不会让病毒分崩离析。
'Our data are very clear, the virus becomes much more stable with the mutation,' Dr Choe said.
Choe博士说:“我们的数据非常清楚，随着变异，病毒变得更加稳定。
That mutation belongs to a strain of coronavirus known as D614G.
这种突变属于- -种被 称为D614G的冠状病毒株。
Researchers at Los Alamos National L aboratory in New Mexico said in March that the mutant Researchers at Los Alamos National L .aboratory in New Mexico said in March that the mutant strain started spreading in early February in Europe.
新墨西哥州洛斯阿拉莫斯国家实验室的研究人员在3月份表示，这种突变菌株于2月初开始在欧洲传播。
It has since made its way to the US, where it became the most common - and aggressive -strain on the East Coast by March, and the scientists there said it's now the world-dominating strain.
自那以后，它已经进入了美国，到3月份，它成为东海岸最常见、最具攻击性的菌株，那里的科学家表示，它现在是世界上占主导地位的菌株。
March, it had only appeared seven times in the sequences uploaded to an international database.
当科学家们在3月份首次报道Spike D614G时，它只在.上传到国际数据库的序列中出现了7次。
Meanwhile, a less potent strain spread from China to Washington state and California, so that the US was bombarded by two different attacks, of different strengths.
与此同时，一个不太强大的菌株从中国蔓延到华盛顿州和加利福尼亚州，以至于美国遭到了两种不同强度的袭击。
'However, an early April sampling of the data from GISAID showed that G61 4's frequency was increasing at an alarming pace throughout March, and it was clearly showing an ever-broadening geographic spread,' the researchers wrote in their report published online on April30.
研究人员在4月30日发布在网上的报告中写道，然而，4月初对GISAID数据的抽样显示，整个3月份G614的频率都在以惊人的速度增加，而且明显显示出地理分布的不断扩大。
It would seem that at some point, the G614mutation and another, D614 mutation, merged to become the D614G mutation.
似乎在某个时候，G614突变和另一个D614突变合并成了D614G突变。
Together they've become dominant, and more infectious through several modes.
它们一起变得占主导地位，并通过几种模式更具传染性。
That previous work, coupled with the new study all but debunks the 'founder effect' theory,which suggests that coronavirus is not very genetically diverse and came from just a few seeds, the Scripps team says.
斯克里普斯团队说，之前的工作，再加上这项新的研究，几乎揭穿了“奠基者效应”理论，该理论表明冠状病毒在基因.上并不是很多样化，只来自几个种子。
'There have been at least a dozen scientific papers talking about the predominance of this mutation,' co-author Dr Michael Farzan says.
合著者迈克尔法赞博士说:“至少有十几篇科学论文在讨论这种突变的主导地位。”
'Are we just seeing a "founder effect?"
“我们只是看到了“奠基者效应'吗? ”
'Our data nails it. It is not the founder effect.'
“我们的数据证实了这一点，这不是奠基者效应。
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