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H********g
发帖数: 43926 | 1 【 以下文字转载自 Military 讨论区 】
发信人: niuheliang (别问我是谁), 信区: Military
标 题: CRISPR的高超技巧
发信站: BBS 未名空间站 (Mon Aug 28 15:12:26 2017, 美东)
早饭的时候读了一公众号的推送。差点没把昨晚的剩饭吐出来。难怪生物千老干的是黑
砖窑。原来大名鼎鼎的CRISPR需要如此高超的技巧。
首先的感觉是CRISPR需要瞎蒙。千老完全没有控制。举例说，时间多少不知道。文章说
6小时以上脱靶问题就严重。好吧，脑补一下就分6管从1小时到6小时做6个实验。看哪
一管最后“显示活性”。尼玛难关重复率低。换别人按你的论文说的要等1小时吧。
Good luck。
其次放狗看看啥叫脱靶：
“操作以后留下的序列是非常随机的，根本无法预测会切割在哪里。根据我们实验室的
测序结果来看，CRISPR-CAS处理后靶序列的缺失位置变化非常大，从21bp的巨大缺失，
到根本无变化的都有，实际编辑位点左右偏移可以达到20bp，有的造成frame shift，
有的只缺失1个或几个氨基酸，有的是一个或数个点突变，有的根本没变化。而因为人
类基因有两个拷贝，这两个等位基因不是同时被切割的，有可能只切割一个，另一个还
是原样，也有可能两个都切割了，但位点和产生的序列还各自不同。”
难怪颜mm提到可重复问题。感情是颜mm针对的不是小韩；而是黑砖窑里人所共知的高超
技巧问题。要多高的技巧才能把根本无变化舔成人类的救星。
本班生物博士这么多。谁来给我这民科科普一下？ | r****z
发帖数: 12020 | 2 哪位行家讲解一下，这是真的吗？这技术完全靠瞎蒙，根本不清楚机理？
其实如果实验理论上确认结果有一定的不确定性，但要能预测产生各个可能结果的几率
并被实验证实，也可以算可以重复吧。
【在 H********g 的大作中提到】
: 【 以下文字转载自 Military 讨论区 】
: 发信人: niuheliang (别问我是谁), 信区: Military
: 标 题: CRISPR的高超技巧
: 发信站: BBS 未名空间站 (Mon Aug 28 15:12:26 2017, 美东)
: 早饭的时候读了一公众号的推送。差点没把昨晚的剩饭吐出来。难怪生物千老干的是黑
: 砖窑。原来大名鼎鼎的CRISPR需要如此高超的技巧。
: 首先的感觉是CRISPR需要瞎蒙。千老完全没有控制。举例说，时间多少不知道。文章说
: 6小时以上脱靶问题就严重。好吧，脑补一下就分6管从1小时到6小时做6个实验。看哪
: 一管最后“显示活性”。尼玛难关重复率低。换别人按你的论文说的要等1小时吧。
: Good luck。
| H********g
发帖数: 43926 | 3 这是转过来供广大千老嘲笑的
【在 r****z 的大作中提到】
: 哪位行家讲解一下，这是真的吗？这技术完全靠瞎蒙，根本不清楚机理？
: 其实如果实验理论上确认结果有一定的不确定性，但要能预测产生各个可能结果的几率
: 并被实验证实，也可以算可以重复吧。
| C*********X
发帖数: 10518 | 4 我已经看不懂技术细节了。。。
【在 H********g 的大作中提到】
: 这是转过来供广大千老嘲笑的
| C*********X
发帖数: 10518 | 5 CRISPR, /ˈkrɪspər/, is a family of DNA sequences in bacteria
that contains snippets of DNA from viruses that have attacked the bacterium.
These snippets are used by the bacterium to detect and destroy DNA from
further attacks by similar viruses. These sequences play a key role in a
bacterial defence system,[2] and form the basis of a genome editing
technology known as CRISPR/Cas9 that allows permanent modification of genes
within organisms.[3]
The CRISPR/Cas system is a prokaryotic immune system that confers resistance
to foreign genetic elements such as those present within plasmids and
phages[4][5][6] that provides a form of acquired immunity. RNA harboring the
spacer sequence helps Cas proteins recognize and cut exogenous DNA. Other
RNA-guided Cas proteins cut foreign RNA.[7] CRISPRs are found in
approximately 40% of sequenced bacterial genomes and 90% of sequenced
archaea.[8][note 1]
CRISPR is an abbreviation of Clustered Regularly Interspaced Short
Palindromic Repeats.[9] The name was minted at a time when the origin and
use of the interspacing subsequences were not known. At that time the
CRISPRs were described as segments of prokaryotic DNA containing short,
repetitive base sequences. In a palindromic repeat, the sequence of
nucleotides is the same in both directions. Each repetition is followed by
short segments of spacer DNA from previous exposures to foreign DNA (e.g., a
virus or plasmid).[10] Small clusters of cas (CRISPR-associated system)
genes are located next to CRISPR sequences.
A simple version of the CRISPR/Cas system, CRISPR/Cas9, has been modified to
edit genomes. By delivering the Cas9 nuclease complexed with a synthetic
guide RNA (gRNA) into a cell, the cell's genome can be cut at a desired
location, allowing existing genes to be removed and/or new ones added.[11][
12][13] The Cas9-gRNA complex corresponds with the CAS III crRNA complex in
the above diagram.
CRISPR/Cas genome editing techniques have many potential applications,
including medicine and crop seed enhancement. The use of CRISPR/Cas9-gRNA
complex for genome editing[14][15] was the AAAS's choice for breakthrough of
the year in 2015.[16] Bioethical concerns have been raised about the
prospect of using CRISPR for germline editing.[17] | C*********X
发帖数: 10518 | 6 技术根本就不是问题。。。
我不想搞技术了。。。。。TM逼的，这个技术到底是要解决什么问题啊。。。
我发现我对狗非常有兴趣，。。。。
我很想用我的动物学硕士找工作。。如果能去做狗的breeder，那是非常爽的。。是不
是。。
一天到晚泡胶不精神病才怪呢，问题是一条到晚泡脚我也没有变精神病啊。。
bacteria
bacterium.
genes
resistance
the
【在 C*********X 的大作中提到】
: CRISPR, /ˈkrɪspər/, is a family of DNA sequences in bacteria
: that contains snippets of DNA from viruses that have attacked the bacterium.
: These snippets are used by the bacterium to detect and destroy DNA from
: further attacks by similar viruses. These sequences play a key role in a
: bacterial defence system,[2] and form the basis of a genome editing
: technology known as CRISPR/Cas9 that allows permanent modification of genes
: within organisms.[3]
: The CRISPR/Cas system is a prokaryotic immune system that confers resistance
: to foreign genetic elements such as those present within plasmids and
: phages[4][5][6] that provides a form of acquired immunity. RNA harboring the
| C*********X
发帖数: 10518 | | C*********X
发帖数: 10518 | 8 你他麻痹的，我都没有未来，绿卡都不知道在哪里，你叫我有什么plan,???
plan你个麻痹！！！神是骗人的！！！
操死他麻痹的神。。我要做一个巨幅banner, Fuck God,挂在我的front yard,我看看来
来往往的车主会怎么想。。 | C*********X
发帖数: 10518 | 9 我这才7年离开学术界啊。。
我的未来到底在哪里？我要干什么。。。
【在 C*********X 的大作中提到】
: 我已经看不懂技术细节了。。。
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