我国科学家开发出比Cas9/sgRNA更优的基因编辑系统

smilingcloud

回复 MP4 的帖子

录音不是发给你的。

从科研圈内的角度去听录音，
结合7月末海外邮件组的内容，
有脑子、有良心的人会有自己判断。

“自己有信心重复”，你当搞科研是卖大力丸啊。
要的是数据！信心顶个球。

MP4

smilingcloud 发表于 2016-8-7 17:51
回复 MP4 的帖子

录音不是发给你的。

[size=1.3em]对啊，调查未出来你判断个球啊。

[size=1.3em]你这叫搞科研么？有智商有良心的人都知道你这叫未审先判，造谣诋毁

四十己过

回复 smilingcloud 的帖子

你只有一只眼，我没什么好说的！你选择你有利的回复，我可以选择一堆有利的网文，但是你想表是我针对的问题吗？

从你来论坛，我就关注过你，你也算是一个对事情事物严谨的文化人，尽然选择可以用一只眼看世界，太令我惊讶？！MP4可能言论上让人觉得生硬，但是他的解释，你读懂了吗？懂的我针对的问题吗？未审就判，更何况针对的是一项有百分一可能性的科学论文？我不知道你哪里来的勇气和战斗力一直纠缠不清！从一个正常人演变到一个斯文扫地的赖皮？？？

最后再劝你几句，对与科学（未知），我们应当抱着谨慎，敬畏，和期待科学真相的心，好吗？ 不要选择性的BBBB个不停！关于这个事件，你要有空，既然看了国外的论坛，也可以请到知乎上参考一些专业人士的想法，可能你也会产生共鸣！ 另外请不要再回复我了，如果你还觉得是我说的不正确，发个私信给我，我可以把说有针对你的回复都删了，让你觉得你是正确的，好吗？

MP4

四十己过 发表于 2016-8-5 19:13
是的，你说的非常正确。
但是目前针对韩，还未上升到学术腐败和政治干扰这一层次，请耐心等待好吗？请不 ...

与此次争议无关的美国乔治城大学神经科学系教授吴建永接受新华社记者采访时表示，可以理解“媒体需要热点，大众需要追星”这类行为，但科研事件往往要在多年后才能做出最终结论，因为许多科研成果的影响因素复杂，需要时间才能辨别真伪。而现在处于未决阶段，一些媒体的报道容易引起有各种倾向性的猜测。
　　吴建永为此写了题为《木桌子效应》的科普文章，回顾历史上著名科学家费米当年用中子引发核裂变，别人却不能重复的故事。费米后来发现原因是他用木桌子，木材中的氢原子有减慢中子的作用，而其他人用大理石桌面，所以不能重复。费米由此进一步总结出慢中子理论，发明了核反应堆。吴建永说：“未知因素影响实验结果，造成实验不能重复，是科研中的普遍现象，应该学会以平常心看待新闻中处于萌芽状态的新发现。”

smilingcloud

爱之深，恨之切。

小保方晴子出事的时候，可以正常走学术渠道。
从韩春雨的各种回应来看，与小保方当时的答记者问如出一辙。

以民族大义来洗地，就立此存照吧。
谁也不用删删改改留言。

2016.8.7

MP4

smilingcloud 发表于 2016-8-7 21:47
爱之深，恨之切。

小保方晴子出事的时候，可以正常走学术渠道。

无罪推定原则是现代法治国家刑事司法通行的一项重要原则，是国际公约确认和保护的基本人权，也是联合国在刑事司法领域制定和推行的最低限度标准之一。

你把无罪推定说成洗地，还说成民族主义那也是彻头彻尾造谣，你以为这样狡辩有用么？

我发过日本你是不是就造个大和民族主义的帽子？

smilingcloud

http://www.nature.com/news/repli ... intensifies-1.20387

Replications, ridicule and a recluse: the controversy over NgAgo gene-editing intensifies

As failures to replicate results using the CRISPR alternative stack up, a quiet scientist stands by his claims.

• David Cyranoski
  

[size=14.495px]08 August 2016

SHIJIAZHUANG, CHINA

[size=14.495px]A controversy is escalating over whether a gene-editing technique proposed as an alternative to the popular CRISPR–Cas9 system actually works.

[size=14.495px]Three months ago, Han Chunyu, a biologist at Hebei University of Science and Technology in Shijiazhuang, reported that the enzyme NgAgo can be used to edit mammalian genes. Now, an increasing number of scientists are complaining that they cannot replicate Han’s results — although one has told Nature[size=14.495px] that he can.

Han says he receives dozens of harassing calls and texts each day, mocking him and telling him that his career is over — but he is convinced that the technique is sound. He also told Nature that he had submitted a detailed protocol to the online genetic-information repository Addgene on 8 August, at Addgene’s request, and hopes that this will help efforts to reproduce his work. Nature Biotechnology, which published the research, is investigating the matter.

The stakes are high. Over the past few years, the CRISPR–Cas9 system has transformed biology. But it has also made scientists hungry for other methods to expand the gene-editing toolkit: NgAgo is one of several that have emerged. “A lot of us are really cheerleading and hoping that it works,” says geneticist George Church of Harvard Medical School in Boston, Massachusetts.

CRISPR–Cas9 uses small genetic sequences to guide an enzyme to cut DNA in a particular location. Inspired, Han looked through the literature for other guidable protein ‘scissors’, and came across a family of proteins called Argonaute, or Ago, that fitted the bill. Others had flagged the proteins as potential gene editors.

In the paper, Han’s team reports using a wide variety of genetic sequences to guide one of these proteins, NgAgo, to edit eight different genes in human cells and to insert genes at specific points on chromosomes (F. Gao et al. Nature Biotechnol.34, 768–773; 2016).

Crucially, NgAgo very specifically cut only the target genes, says Han, unlike CRISPR–Cas9, which sometimes edits the wrong genes. And whereas CRISPR–Cas9 requires a certain genetic sequence to be near the cutting site to initiate its activity, NgAgo does not, which could broaden its potential applications, adds Han.

The initial reaction to the work in China was laudatory, including a visit to the lab by China Central Television. It was overwhelming, says Han, who is a reclusive figure. His hobbies include collecting teas and playing an ancient stringed instrument called the guqin. He doesn’t like to travel and has never left China: a trip to visit a collaborator in Hangzhou in March was the first time the 42 year old had boarded a plane. Before his paper came out, “I was completely unknown”, says Han, who spoke to Nature at his laboratory and a nearby restaurant.

Doubts about the research first surfaced at the beginning of July, when Fang Shimin, a former biochemist who has become famous for exposing fraudulent scientists, wrote on his website New Threads (xys.org) that he had heard reports of failed reproduction efforts, and alleged that Han’s paper was irreproducible. Criticism grew on various Chinese sites.

On 29 July, the controversy went inter­national when Gaetan Burgio, a geneticist at the Australian National University in Canberra, posted thorough details of his failed attempts to replicate the experiment on his blog. Normally, his posts get a few dozen hits, but this one spiked to more than 5,000.

On the same day, geneticist Lluís Montoliu, at the Spanish National Centre for Biotechnology in Madrid, e-mailed his colleagues at the International Society for Transgenic Technologies to recommend “abandoning any project involving the use of NgAgo” to “avoid wasting time, money, animals and people”. The e-mail was leaked and posted on Fang’s website.

Since then, an online survey by Pooran Dewari, a molecular biologist at the MRC Centre for Regenerative Medicine in Edinburgh, UK, has found only 9 researchers who say that NgAgo works— and 97 who say that it doesn’t.

Two researchers who initially reported success with NgAgo in an online chat group now say that they were mistaken. Debojyoti Chakraborty, a molecular biologist at the CSIR-Institute of Genomics and Integrative Biology in New Delhi, says that he repeated a specific section of Han’s paper that described using NgAgo to knock out a gene for a fluorescent protein that had been introduced into a cell. The glow was reduced, so Chakraborty assumed that NgAgo had disabled the gene. But after sequencing the DNA, he found no evidence of gene editing. He now says that the reduction in fluorescence must have had some other cause.

Jan Winter, a PhD student in genomics at the German Cancer Research Center in Heidelberg, says that he had a similar experience. “I will retry the experiment in the upcoming weeks, but so far I think it won’t work,” he says.

[size=14.495px]

Han says that he has only got the system to work on cells cultured in his laboratory, and it failed in cells that he purchased. He later found the purchased cells to be contaminated with bacteria called mycoplasma, and says that others might be having the same problem. He adds that some graduate students might be working too fast and not being careful with reagents. Winter disagrees: “I do not think it is a problem of the scientists doing something wrong.”

One researcher in China, who works independently from Han’s research group and who doesn’t want his name to be entangled in the public controversy, told Nature that he had tested NgAgo in a few kinds of cell and found that it was able to induce genetic mutations at the desired sites — a finding that he verified by sequencing. He adds that the process was less efficient than CRISPR–Cas9, and requires tweaking to improve the efficiency. “But, in short, it worked,” he says.

Two more Chinese scientists, who also asked not to be named, say they have initial results showing that NgAgo works but still need to confirm with sequencing.

“It might, might work,” says Burgio, “but if so, it’s so challenging that it’s not worth pursuing. It won’t surpass CRISPR, not by a long shot.”

The failure of NgAgo “would be disappointing, but then there is work for us left to do to see whether other Argonaute systems can get it to work somehow,” says microbiologist John Van der Oost of Wageningen University in the Netherlands, a co-author of the 2014 analysis of Argonaute proteins that laid the groundwork for their use in gene editing (D. C. Swaarts et al. Nature 507, 258–261; 2014).

This week, Nature Biotechnology sent a statement to Nature’s news team, saying that “several researchers” have contacted the journal to report that they cannot reproduce the results, and that “the journal is following established process to investigate the issues”. A spokesperson declined to comment on the nature or duration of the investigation. (Nature Biotechnology is published byNature’s publisher, Springer Nature; Nature’s news and comment team is editorially independent of the publisher’s research editorial teams.)

Hebei University says that it will ask Han to repeat the experiment so that it can be verified by an independent party within a month, according to Chinese state media.

Nature 536, 136–137 (11 August 2016) doi:10.1038/536136a

StephenW

复制，嘲笑和隐士：在争论NgAgo基因编辑加剧

至于失败的复制使用CRISPR替代叠起来的结果，一个安静的科学家坚持自己的要求。

    大卫希拉诺斯基

2016年08月08日更新：

    2016年08月09日

石家庄，中国

生物学家汉淳于收到几十个骚扰电话和短信的每一天，但他坚信自己的基因编辑纸张的声音。

争议不断升级在是否提议作为一种替代流行的CRISPR-Cas9系统实际工作的基因编辑技术。

三个月前，韩春雨，在河北科技大学在石家庄的生物学家，报告说，这种酶NgAgo可以用来编辑哺乳动物基因。现在，越来越多的科学家都在抱怨，他们无法复制韩寒的结果 - 尽管一位研究员告诉大自然，他可以。自然生物技术，其发表的研究，正在调查此事。

韩寒说他收到几十个，每天的骚扰电话和短信，嘲笑他，并告诉他，他的职业生涯已经结束 - 但他坚信该技术是健全的。 8月8日，他提交了一份协议，以在线的遗传信息资源库Addgene。他希望这将有助于努力重现他的工作，但其他科学家说，它没有明确的事情了。

赌注是很高的。在过去的几年中，CRISPR-Cas9系统改变了生物学。但它也使科学家们饿了其他方法来扩大基因编辑工具：NgAgo是已经出现的几个之一。 “我们很多人真的啦啦队，并希望它的作品，”哈佛医学院马萨诸塞州波士顿市的遗传学家乔治教堂说。

CRISPR-Cas9使用小的基因序列，引导一种酶切割DNA的特定位置。启发，汉通过文献其他引导的蛋白质“剪刀”看了看，并在蛋白质家族被称为Argonaute蛋白，或以前，即装账单来了。其他人的标记蛋白作为潜在的基因编辑器。


原生物化学方舟子涉嫌在他的网站上看到，NgAgo文件是不可复制的。

在造纸，大族使用各种基因序列，以指导这些蛋白质，NgAgo之一，队报告编辑在人类细胞八个不同的基因，并在染色体上插入的特定时间点的基因（F. Gao等人，Nature生物工程。 34，768-773; 2016）。

汉，不像CRISPR-Cas9，有时编辑错误的基因说，最重要的是，NgAgo很明确只下调靶基因。和而CRISPR-Cas9需要一定的遗传序列是切割位点附近启动其活性，NgAgo没有，这可能扩大其潜在的应用，增加了啥。

在中国工作的最初反应是赞美，包括中国中央电视台到实验室参观。这是压倒性的汉，谁是深居简出的图说。他的爱好包括收集茶和打称​​为古琴一个古老的弦乐器。他不喜欢旅行，从来没有离开中国：一个旅程，参观了在杭州的合作者在三月第一次42岁就登上了飞机。之前他的论文就出来了，“我当时完全不知道”，汉，谁以自然在他的实验室，附近的餐厅说。

有关研究的质疑首次出现在七月初，当方舟子，前生物化学谁已成为著名的揭露欺诈科学家，写在他的网站新语丝（xys.org），他听说未能再现努力的报告，据称，韩寒的文章是不可复制的。批评生长在中国各个网站。


遗传学家加埃唐布尔焦发表失败尝试复制在自己的博客中NgAgo实验。

7月29日，争论了国际时的Gaetan布尔焦，在堪培拉的澳大利亚国立大学的遗传学家，张贴了他的失败尝试复制在自己的博客实验的全部详细信息。通常情况下，他的帖子得到了几十个命中，但是这一次飙升到超过5000人。

就在同一天，遗传学​​家LLUIS Montoliu，在马德里的西班牙国家生物技术中心，通过电子邮件发送他在国际社会对转基因技术的同事推荐“弃涉及使用NgAgo的任何项目”，以“避免浪费时间，金钱，动物和人。“该电子邮件被泄露，并公布在方舟子的网站。

此后，由Pooran Dewari，在MRC再生医学中心在爱丁堡，英国分子生物学家的网上调查，发现只有9研究人员说，谁NgAgo作品 - 和97谁说，事实并非如此。

谁最初报道NgAgo成功的网上聊天组中的两个研究人员现在说他们错了。 Debojyoti Chakraborty的，在基因组学和新德里综合生物学CSIR研究所的分子生物学家说，他重复使用NgAgo淘汰了已被引入细胞中的荧光蛋白的基因所描述韩寒的文章的特定部分。辉光降低，所以Chakraborty的假定NgAgo已经禁用的基因。但测序的DNA后，他没有发现任何基因编辑的证据。现在，他说，在荧光的减少一定有一些其他的原因。

扬冬季，博士生在德国癌症研究中心的海德堡基因组学，说他有过类似经历。 “我将重试实验在未来几周，但到目前为止，我认为这是行不通的，”他说。


遗传学家LLUIS Montoliu建议放弃涉及基因编辑使用NgAgo的任何项目。

韩寒说，他只得到了系统在他的实验室培养的细胞工作，并在他购买的细胞失败。后来，他发现所购细胞对细菌叫支原体污染，并说其他人可能有同样的问题。他补充说，一些毕业生可能会工作得太快，不小心用试剂。冬季不同意：“我不认为这是科学家们做错事的问题。”

在中国的一位研究人员，谁从汉的研究小组独立工作，谁不希望在公众的争议被缠住了他的名字，叫自然，他在几种电池的测试NgAgo，发现它能够诱导基因他通过测序验证这一发现 - 在所需地点的突变。他补充说，过程比CRISPR-Cas9效率较低，需要调整，以提高效率。 “不过，总之，它的工作，”他说。

两名中国科学家，谁也不愿透露姓名，说他们有表明NgAgo工作，但仍然需要测序证实了初步成效。

“也许，可能的工作，说：”布尔焦“，但即便如此，它是如此具有挑战性的，它不是值得追求的。它不会超过CRISPR，而不是由一个长镜头。“

布尔焦说，有一点，就是在Addgene修改后的新协议。还有就是要保持细胞的镁含量的警告“，但没有任何意义，我，”他说。它也警告不要支原体污染。但是Montoliu，现在谁可能会给NgAgo一次机会在九月，怀疑这可能占所有报告的问题。

NgAgo的失败“将是令人失望的，但后来有工作，为我们来办看其他的Argonaute系统是否能得到它以某种方式工作，”荷兰瓦赫宁根大学的微生物学家约翰·范德奥斯特在荷兰的合着者说的2014年分析认为，奠定了其在基因编辑使用Argonaute蛋白的（DC Swarts等自然507，258-261; 2014）。

本周，自然生物技术发来声明，以大自然的新闻队伍，他说，“一些研究人员”已经联系该杂志报道，他们无法重现的结果，而且“杂志是按照既定程序进行调查的问题”。一位发言人拒绝就调查的性质和持续时间发表评论。 （自然生物技术是通过自然的出版商出版，施普林格自然;自然的新闻和评论团队编辑独立出版商的研究编辑团队的。）

河北大学说，它会问啥重复实验，以便它可以在一个月内独立方进行核实，据中国官方媒体。

    性质
    536，
    136-137
    （2016年11月）
    DOI：10.1038 / 536136a

smilingcloud

http://www.nature.com/news/beyond-crispr-a-guide-to-the-many-other-ways-to-edit-a-genome-1.20388?WT.mc_id=TWT_NatureNews

Beyond CRISPR: A guide to the many other ways to edit a genome

The popular technique has limitations that have sparked searches for alternatives.

• Heidi Ledford
  

08 August 2016 Corrected:

• 09 August 2016
  

Laguna Design/SPL
Argonaute proteins (model pictured) are one of many potential alternatives to the CRISPR–Cas9 gene-editing system.
The CRISPR–Cas9 tool enables scientists to alter genomes practically at will. Hailed as dramatically easier, cheaper and more versatile than previous technologies, it has blazed through labs around the world, finding new applications in medicine and basic research.

But for all the devotion, CRISPR–Cas9 has its limitations. It is excellent at going to a particular location on the genome and cutting there, says bioengineer Prashant Mali at the University of California, San Diego. “But sometimes your application of interest demands a bit more.”

The zeal with which researchers jumped on a possible new gene-editing system called NgAgo earlier this year reveals an undercurrent of frustration with CRISPR–Cas9 — and a drive to find alternatives. “It’s a reminder of how fragile every new technology is,” says George Church, a geneticist at Harvard Medical School in Boston, Massachusetts.  

A mini-me
CRISPR–Cas9 may one day be used to rewrite the genes responsible for genetic diseases. But the components of the system — an enzyme called Cas9 and a strand of RNA to direct the enzyme to the desired sequence — are too large to stuff into the genome of the virus most commonly used in gene therapy to shuttle foreign genetic material into human cells.

A solution comes in the form of a mini-Cas9, which was plucked from the bacterium Staphylococcus aureus1. It’s small enough to squeeze into the virus used in one of the gene therapies currently on the market. Last December, two groups used the mini-me Cas9 in mice to correct the gene responsible for Duchenne muscular dystrophy2, 3.

Expanded reach
Cas9 will not cut everywhere it’s directed to — a certain DNA sequence must be nearby for that to happen. This demand is easily met in many genomes, but can be a painful limitation for some experiments. Researchers are looking to microbes to supply enzymes that have different sequence requirements so that they can expand the number of sequences they can modify.

One such enzyme, called Cpf1, may become an attractive alternative. Smaller than Cas9, it has different sequence requirements and is highly specific4, 5.

Another enzyme, called C2c2, targets RNA rather than DNA — a feature that holds potential for studying RNA and combating viruses with RNA genomes6.

True editors
Many labs use CRISPR–Cas9 only to delete sections in a gene, thereby abolishing its function. “People want to declare victory like that’s editing,” says Church. “But burning a page of the book is not editing the book.”

Those who want to swap one sequence with another face a more difficult task. When Cas9 cuts DNA, the cell often makes mistakes as it stitches together the broken ends. This creates the deletions that many researchers desire.

But researchers who want to rewrite a DNA sequence rely on a different repair pathway that can insert a new sequence — a process that occurs at a much lower frequency than the error-prone stitching. “Everyone says the future is editing many genes at a time, and I think: ‘We can’t even do one now with reasonable efficiency’,” says plant scientist Daniel Voytas of the University of Minnesota in Saint Paul.

But developments in the past few months have given Voytas hope. In April, researchers announced that they had disabled Cas9 and tethered to it an enzyme that converts one DNA letter to another. The disabled Cas9 still targeted the sequence dictated by its guide RNA, but could not cut: instead the attached enzyme switched the DNA letters, ultimately yielding a T where once there was a C7. A paper published in Science last week reports similar results8.

Voytas and others are hopeful that tethering other enzymes to the disabled Cas9 will allow different sequence changes.

Pursuing Argonautes
In May, a paper in Nature Biotechnology9 unveiled an entirely new gene-editing system. Researchers claimed that they could use a protein called NgAgo to slice DNA at a predetermined site without needing a guide RNA or a specific neighbouring genome sequence. Instead, the protein — which is made by a bacterium — is programmed using a short DNA sequence that corresponds to the target area.

The finding kicked off a wave of excitement and speculation that CRISPR–Cas9 would be unseated, but laboratories have so far failed to reproduce the results. Even so, there is still hope that proteins from the family that NgAgo belongs to — known as Ago or Argonautes — made by other bacteria could provide a way forward, says genome engineer Jin-Soo Kim at the Institute for Basic Science in Seoul.

Programming enzymes
Other gene-editing systems are also in the pipeline, although some have lingered there for years. For an extensive project that aimed to edit genes in bacteria, Church’s lab did not reach for CRISPR at all. Instead, the team relied heavily on a system called lambda Red, which can be programmed to alter DNA sequences without the need for a guide RNA. But despite 13 years of study in Church’s lab, lambda Red works only in bacteria.

Church and Feng Zhang, a bioengineer at the Broad Institute of MIT and Harvard in Cambridge, Massachusetts, say that their labs are also working on developing enzymes called integrases and recombinases for use as gene editors. “By exploring the diversity of enzymes, we can make the genome-editing toolbox even more powerful,” says Zhang. “We have to continue to explore the unknown.”

Nature 536, 136–137 (11 August 2016) doi:10.1038/536136b

smilingcloud

需要翻墙才能看到
https://groups.google.com/forum/m/#!topic/crispr/V1FALNbspCo

有关N gAgo技术的邮件组讨论过程。

挺韩大将科学网 岳东晓（物理博士）在生物专业人士前侃侃而谈，“做不出来NgAgo是技术不行”。
结果遭到惨痛攻击。
岳已经宣布退出讨论了。

讨论用词尖刻，以后本版也努力学习吧。