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全部话题 - 话题: mutating
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l**********1
发帖数: 5204
1
En
温习一下 其十一年前的豪言 啊
中国科学:显著的发展和严峻的挑战
——历史演变和现状比较
于2001年12月4日 1st version
饶毅
本文在简要回顾中国科学史的基础上,介绍一些近年研究的内容,肯定中国
科学令人乐观的进步,并讨论可能的意义。同时也指出,中国优秀论文总量仍不
到世界的百分之一,低于中国经济在世界所占的百分比、也不能适应中国持续发
展的要求。中国科学的规模需要相当程度的扩大、质量有待进一步提高。中国科
技还存在面临许多问题和挑战。
中国科学历史上的优秀例子
一个国家科学研究状况可以近似地由发表论文的情况所反映。以下,本文主
要从生命科学的研究来讨论中国科学的情况,一方面这是我有一定判断力的领域,
另一方面生命科学是科学技术最重要的组成部分之一,可以反映科学主流。讨论
中国论文发表情况前,先谈两个背景:中国科学的历史情况,优秀科学和著名杂
志的关系。
奠定中国生命科学研究是二、三十年代协和医学院生理系林可胜和生化系吴
宪。他们不仅自己研究出色,而且培养和带领了其他研究者。林可胜在胃肠道生
理和神经生理有优秀工作。1942年,他在中国当选为美国科学院外籍院士,是... 阅读全帖
g*********3
发帖数: 177
2
我本人并不是说NGS对cancer研究没用,只是说不会产生革命性的突破~
1)NGS穷举出mutation不会很难,这也是NGS牛逼的地方,但是真正找到driver很难
2)在function研究方面,无论是RNA-Seq还是ChIP-Seq说的都是一个故事:
transcription,一些初步的数据已经证实protein level翻译水平的贡献率大概是2/3,
另外我觉得NGS的定量分析和microarray一样很丑陋
3)我比较赞同进化的观点,因为cancer不能完全归功于mutation~ LS有两位在讨论
reprogrammed signal pathway~ 这个当然有mutation的例子,但是和mutation无关的
例子简直是太多了~ e.g.a lot of weird metabolism pathways will totally rewire
the epigenetic profiling. Some abnormal metabolites can change the pathway.
.....the interaction between dif... 阅读全帖
l**********1
发帖数: 5204
3
上图 SD its means
下图 SEM its mean
Btw,
降低 bias 就可能 增大 SEM的 error 拿测量甲地 乙地 女子的身高来作为例子
乙地的 习格格 陈小丹格格 的 身高 岂是 甲地的 芙蓉姐姐 凤姐等的身高 一样容
易测到的 哈 (NB: 钻 北方 南方地域贴的 请左拐 进菌版八区 在那里撸管)

pls refer
Sanjuan R.
From Molecular Genetics to Phylodynamics: Evolutionary Relevance of Mutation
Rates Across Viruses
PLoS Pathog. (2012) 8: e1002685.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3342999/
its pp5 left column
>To reducing bias, this method
accounts for phylogenetic relatedness (on the other hand, it
in... 阅读全帖
l**********1
发帖数: 5204
4
上图 SD its means
下图 SEM its mean
Btw,
降低 bias 就可能 增大 SEM的 error 拿测量甲地 乙地 女子的身高来作为例子
乙地的 习格格 陈小丹格格 的 身高 岂是 甲地的 芙蓉姐姐 凤姐等的身高 一样容
易测到的 哈 (NB: 钻 北方 南方地域贴的 请左拐 进菌版八区 在那里撸管)

pls refer
Sanjuan R.
From Molecular Genetics to Phylodynamics: Evolutionary Relevance of Mutation
Rates Across Viruses
PLoS Pathog. (2012) 8: e1002685.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3342999/
its pp5 left column
>To reducing bias, this method
accounts for phylogenetic relatedness (on the other hand, it
in... 阅读全帖
p*****c
发帖数: 20445
5
来自主题: Biology版 - The 2013 HHMI Investigators
A-D E-K L-P R-Z




Peter Baumann, Ph.D.
HHMI Early Career Scientist
Stowers Institute for Medical Research
Peter Baumann’s research focuses on beginnings and endings: beginnings in
the form of reproduction in unisexual lizards and endings in the form of the
telomeres that protect chromosome tips.
Each time chromosomes are copied, telomeres—specialized stretches of DNA
that extend from the ends of each chromosome—become progressively shorter.
With each cell division, they ero... 阅读全帖
l**********1
发帖数: 5204
6
Before NGS 2.0 or 3.0 Illumina platform can read enough longer different
isoforms within Exome sequencing and systems biology aspect,
it is still elusive to answer the linkage between SNP2.0 or 3.0 alternative
splicing with
syndromic disease...
Pls check,
>Although previously described in TS, no CACNA1C mutations have been
reported for
>non-syndromic LQTS. With our functional studies confirming Cav1.2 gain-of-
function as the cellular basis for the CACNA1C mutation-positive patient’s
LQTS pheno... 阅读全帖
l**********1
发帖数: 5204
7
Before NGS 2.0 or 3.0 Illumina platform can read enough longer different
isoforms within Exome sequencing and systems biology aspect,
it is still elusive to answer the linkage between SNP2.0 or 3.0 alternative
splicing with
syndromic disease...
Pls check,
>Although previously described in TS, no CACNA1C mutations have been
reported for
>non-syndromic LQTS. With our functional studies confirming Cav1.2 gain-of-
function as the cellular basis for the CACNA1C mutation-positive patient’s
LQTS pheno... 阅读全帖
h********n
发帖数: 4079
8
来自主题: Biology版 - 请教一下cancer subtype的问题
肿瘤的分类, 以往都是按组织学分类的, 比如 lung adenocarcinoma, small cell
carcinoma, squamous cell carcinoma都是肺癌的subtype. 在肺癌里, 我还没听说过
有subtype上混合的, 但确实有undifferentiated lung cancer, 细胞分化程度低, 不
好分类.
如果从molecular subtype上分类, 比如有些肺癌病人有kras mutation, 有些有EGFR
mutation, 等等, 如果你要问会不会互相转变, 这个很难证明, 因为肿瘤切下来的时候
是啥样的就啥样, 但不同基因的变化是积累性的. 通常的假设是至少两个genetic
change. 所以有可能肿瘤早期只有一个mutation, 后来mutation多起来了.
另外, 很多实体瘤都是clonal tumor, 就是说一个肿瘤大都是由一个癌细胞分裂生长而
来的. 所以, 同一个病人身上的某个肿瘤里面的已有的genetic change不会变回正常的
, 而随着肿瘤的进展/复发, 有可能有新的mutation. ... 阅读全帖
r*****m
发帖数: 3619
9
来自主题: Biology版 - Wang Jun这么狠了吗?
单细胞测序哪里不靠谱?不但是华大,其他国家的测序中心也发表了类似的结论。靶向
治疗的核心是什么?是寻找 driver mutation, 已有的靶向药杀掉敏感癌细胞之后,根
本不会再找到有规律的 driver mutation,如果有的话,早就被找到发表了,不要测序
技术,拿常规遗传学方法也找到了。测序技术只是最后敲响了这个学科的丧钟。
最要命的是根本法预测下一个 driver mutation, 不同的癌细胞有上千个 driver
mutation, 转移到脑子的和转移到肝的癌细胞有不同的 driver mutation
r******g
发帖数: 600
10
来自主题: Biology版 - NIH钱多了不少了,是福是祸?
最近 对这个领域 稍微研究了一下,懂得不多,只是提提个人观点
其实你们两个人 说的是对的
你可能看过RP Lifton的papers。他一直致力于 研究 rare mendelian diseases。 他
目前和BCM,Wash U@SL 和 JHU 一起在做 mendelian genetics consortium。 通过在
全世界找 “extreme phenotype - disease outliers” 和 “inbred family的疾病”
来寻找 human knockout的phenotype。
通过 RP Lifton的实验,你发现,这个世界上 仍然有很多 monogenic的病。 但是从
临床的角度来考虑, 研究 monogenic的疾病 究竟有治疗价值吗? 1/100,000 的
mutation导致的 rare disease, 有哪个药厂会愿意生产药物来治疗呢? 所以,工业圈
自然也不会对这个领域感兴趣...
但是,你如果仔细听听RP lifton的讲座,你会发现 “发现rare disease其实并不是RP
lifton的目的”!! 通过 研究 ext... 阅读全帖
r******g
发帖数: 600
11
来自主题: Biology版 - NIH钱多了不少了,是福是祸?
最近 对这个领域 稍微研究了一下,懂得不多,只是提提个人观点
其实你们两个人 说的是对的
你可能看过RP Lifton的papers。他一直致力于 研究 rare mendelian diseases。 他
目前和BCM,Wash U@SL 和 JHU 一起在做 mendelian genetics consortium。 通过在
全世界找 “extreme phenotype - disease outliers” 和 “inbred family的疾病”
来寻找 human knockout的phenotype。
通过 RP Lifton的实验,你发现,这个世界上 仍然有很多 monogenic的病。 但是从
临床的角度来考虑, 研究 monogenic的疾病 究竟有治疗价值吗? 1/100,000 的
mutation导致的 rare disease, 有哪个药厂会愿意生产药物来治疗呢? 所以,工业圈
自然也不会对这个领域感兴趣...
但是,你如果仔细听听RP lifton的讲座,你会发现 “发现rare disease其实并不是RP
lifton的目的”!! 通过 研究 ext... 阅读全帖
b*******s
发帖数: 954
12
来自主题: MedicalCareer版 - Step 1 两道题请教!
第一道题,在elora 以及jbh2009的回答上,再补充一下
是Fragile X。
(1) X-link的疾病,现在的看法是x-dominant或者x-recessive的提法签妥当(请看
uptodate或者其他资源)
(2) 对Fragile X来说,5'-UTR的CGG有expansion.
Normal: CGG repeats < 45
Grey zone: 45 < CGG repeats < 55
Premutation: 55 < CGG repeats < 200
Premutation由于有较长的5'-UTR转录出的RNA, 这些RNA可能会特别稳定,作为sink,
和一些重要的蛋白作用,影响这些蛋白的功能。
Full mutation: 200 < CGG repeats
Full mutation的5'UTR被methylated, FXMR蛋白无法表达
Premutation和full mutation的重要差别是premutation仍然可以表达FXMR蛋白。所以
premutation和full mutation的症状非常不一样。premutation... 阅读全帖
M***7
发帖数: 2420
13
有一个pool,每个数据自带两个属性: mutation, goodMutation.
goodMutation / mutation 的RATIO 高于0.5认为是signifcant。
假设在N个mutation里得到K个goodMutation的可能性follow binomial distribution。
我现在想定一个mutation的cutoff,mutation > cutoff and ratio > 0.5的认为是
VALID.
哪位给指条路。谢谢
D*********n
发帖数: 279
14
来自主题: Military版 - Native Americans in the United States
http://en.wikipedia.org/wiki/Native_Americans_in_the_United_Sta
Native Americans in the United States
From Wikipedia, the free encyclopedia
Jump to: navigation, search
"American Indian" redirects here. For other indigenous peoples, see
Indigenous peoples of the Americas and other geographic regions. For
Americans from South Asia, see Indian American.
This article may be too long to read and navigate comfortably. Please
consider splitting content into sub-articles and/or condensing it. (January
2... 阅读全帖
x****6
发帖数: 4339
15
来自主题: Military版 - 预测露露和娜娜的未来 (转载)
叔是负责人的千少,下面是叔预测的依据:
http://book.bionumbers.org/what-is-the-mutation-rate-during-genome-replication/
“With ≈3×109 bp in the human genome the mutation rate leads to about 10-8
mutations/bp/generation x 3×109 bp/genome ≈ 10-100 mutations per genome
per generation (BNID 110293). ”
突变会自然发生,平均一个基因组 在一个世代内,会积累10-100个突变。而Cas9脱靶
的个数我记得是每个细胞10左右,那么被编辑的露露和娜娜的基因组的实际突变率是
20-110个突变每代,并不是特别显著的增加。
那么自然人自己就有10-100个随机突变而保持健康,现在加10个;大概率的makes no
difference.

发帖数: 1
16
一个加州理工毕业的说(引用他的话,是用来驳斥的。在没有RaTG13之前,他说的其实
有理。)

I performed BLASTn and Clustal alignment on the Wuhan coronavirus and cross-
annotated missing CDS regions. I found that Bat SARS-like CoVZXC21 and Bat
SARS-like CoVZC45 are the most similar coronaviruses. The sequences are
different at quite a few silent point mutations but sufficiently close (95-
93%) to indicate a lineage that has not diverged significantly- this is a
recent strain with a close common ancestor. Some regions don’t even have
sile... 阅读全帖

发帖数: 1
17
Puma2019 发于 2020-01-29 08:58, 论坛:
标 题: 跟一个朋友聊了会,这次武汉病毒不像合成的。
quote 如下:
I performed BLASTn and Clustal alignment on the Wuhan coronavirus and cross-
annotated missing CDS regions. I found that Bat SARS-like CoVZXC21 and Bat
SARS-like CoVZC45 are the most similar coronaviruses. The sequences are
different at quite a few silent point mutations but sufficiently close (95-
93%) to indicate a lineage that has not diverged significantly- this is a
recent strain with a close common ancestor. Some region... 阅读全帖
t**x
发帖数: 20965
18
再给大家看看作恶的德国医生:
别的地方没法做。全世界都是这么黑,没办法。 给大家看看德国医生的信:
这个医生向数据库汇报我们宝宝便宜的基因是benign的, 他从来没有看过这种变异:
Dear Dr. Xie,
no, I had never seen a patient with this mutation and my information is
bases solely on the published literature.
同一个医生还这么说
Dear Dr. Young,
please see the links below, where I got the information, that this mutation
is a „benign“ mutation. If you happen to have a patients with this
mutations with a sever phenotype it would certainly be worth to be published.
Regards
Thomas Wieser
https... 阅读全帖
h**6
发帖数: 4160
19
把楼主的代码翻译成c++了,输出为Hello。
#include
void mutate(const char *o)
{
o = "Goodbye";
}
int main ()
{
const char *o = "Hello";
mutate(o);
printf("%s\n", o);
return 0;
}
如果mutate函数定义为void mutate(const char *&o),则输出为Goodbye。
n***s
发帖数: 10056
20
Two mutations, the valine to leucine mutation (V419L) and the leucine to
isoleucine mutation (L925I) in voltage-gated sodium channel α-subunit gene,
have been identified as responsible for knockdown resistance to
deltamethrin in bed bugs. One study found that 88% of bed bug populations in
the US had one, the other, or both mutations, meaning that deltamethrin
resistance among bed bugs is currently making this insecticide obsolete.
而且有毒呵
l*h
发帖数: 4124
21
来自主题: Medicine版 - 婶婶肺癌Gefitinib产生抗药求意见
she did pretty well. about 50% develop resistance at 6 months. after
treatment, the # of mutations per tumor is much higher than that before
treatment.
if she still want to take the active/proactive approach, AND if new tumor
samples can be obtained, here are the recommendations:
1. test EGFR mutations in the new sample
2. test RAS mutations in the new sample
if RAS is mutated, the chance of EGFR inhibitors to work is very low. then
focused, multipoint radiation therapy should be considered the ... 阅读全帖
l*h
发帖数: 4124
22
来自主题: Medicine版 - 婶婶肺癌Gefitinib产生抗药求意见
she did pretty well. about 50% develop resistance at 6 months. after
treatment, the # of mutations per tumor is much higher than that before
treatment.
if she still want to take the active/proactive approach, AND if new tumor
samples can be obtained, here are the recommendations:
1. test EGFR mutations in the new sample
2. test RAS mutations in the new sample
if RAS is mutated, the chance of EGFR inhibitors to work is very low. then
focused, multipoint radiation therapy should be considered the ... 阅读全帖
c**i
发帖数: 6973
23
来自主题: NextGeneration版 - Male Infertility Among Chinese Men
Pam Belluck, Study Links Male Infertility to a Missing Protein; A mutation
may be a hurdle to conception, with a sperm viewed as an invader. New York
Times, July 21, 2011.
http://www.nytimes.com/2011/07/21/us
/21fertility.html?scp=1&sq=infertility%20china&st=cse
(a) Quote:
"Men with two copies of the defective gene do not produce the protein.
"besides the 25 percent of men with two mutated copies, half of men have one
mutated and one normal copy with no effect on fertility
(b) Note:
(i) The repo... 阅读全帖
m**********e
发帖数: 2808
24
(我这里不是说40+男人不能生,而是这些男人以及他们的伴侣应该明白风险。这和一
个40+女人坚持要生孩子时,她和她的伴侣应该知道风险是一样道理。这么多人劝女人
要早生,和想要孩子的男人不要选择40+女人,这个研究恰恰就是说,在生养这个问题
上,男女是半斤八两)
高龄父亲给孩子的不好影响已经有很多研究出来,不过大部分都是epidemiological
ones。这次有新研究出来通过描出全部基因序列来量化了此效果。而且证实父亲高龄的
不好影响的来源:
精子是不断分裂产生的,在分裂过程必定有mutation errors,分裂次数越多,这些错
误会积累。所以精子特别容易老化。相对而言,因为卵子是女人还在胎儿时就产生,所
以老化迹象不明显。
这些是mutation errors,是在复制时信息的丢失(比如在电脑里面复制文件,会有不
是100%的复制),和体能等无关。当然,我估计和环境应该有关,可能离辐射近的人影
响会大些。
这次冰岛的研究量化了mutation的错误大约16年翻一番。这些mutation很可能是autism
和schizophrenia的来源。
http://www.scien... 阅读全帖
B********e
发帖数: 19317
25
来自主题: Belief版 - 大家来学习,进化论101
=============side trip================
http://evolution.berkeley.edu/evolibrary/article/side_0_0/types_01
Types of mutations
Knowing a few basic types of mutations can help you understand why some
mutations have major effects and some may have no effect at all.
Substitution
A substitution is a mutation that exchanges one base for another (i.e., a
change in a single "chemical letter" such as switching an A to a G). Such a
substitution could:
1. change a codon to one that encodes a differe
E*****m
发帖数: 25615
26
要反進化論好歹要反人家相信的東西,自己樹立個稻草人打得不亦樂乎
做什麼?
拜託讀點書,讓別人有理由尊重你。
http://www.pbs.org/wgbh/evolution/library/faq/cat01.html
7. Is evolution a random process?
Evolution is not a random process. The genetic variation on which
natural selection acts may occur randomly, but natural selection itself is
not random at all. The survival and reproductive success of an individual is
directly related to the ways its inherited traits function in the context
of its local environment. Whether or not an individu... 阅读全帖
l**********t
发帖数: 5754
27
IF you are a molecular genetics major, briefly explain and enlighten me with
the root cause of mutation in a determinstic fashion WITHOUT resorting to
uncertain replication error or chemical modifications, and their role played
in introduction of new genes during evolution.
Don't quote me genetic engineering examples with target mutations or cross-
breding becuase they just serve to support the intel-design.
Your "non-directional mutation"(netrual drifts) is still a superficial
explanation for v... 阅读全帖
t*******d
发帖数: 2570
28
No, we have not reached agreement on the key point.
The evolution theory science is silent on the root cause of the mutations
because scientists don't know. So they say they don't know. They say the
mutations are random because they are non-directional compared to the
directional survival result. If they find evidence suggesting that the
mutations are directional, they will say the mutations are directional or
patterned or any adjective that can describe whatever pattern they found.
They say wha... 阅读全帖
c******r
发帖数: 889
29
Gosh, mutation happens all the time.
Read about HIV virus resistance and bacterial drug resistance.
And how do you think cancers occur? Not by random mutation but by some divine
intervention? How benevolent.
As for the questions he asked, those are in two different contexts.
The first one, yes, it is so small that we can rule out the same insertion
sites are due to two independent events. Fair enough, in science, we tend to
avoid extreme terms, so no responsible biologist would say its absolutel... 阅读全帖
t*******d
发帖数: 2570
30
Maybe you want to check the following link before claiming sequential
mutations with selection is no better than simultaneous multiple mutations
if mutations are independent. As long as the intermediates have survival
advantage, it is different and it is quite different.
http://en.wikipedia.org/wiki/Weasel_program

new
the
mutations are independent.
w*********r
发帖数: 3382
31
来自主题: TrustInJesus版 - 我相信沒有神(譯)
all we said was it CAN BE random, but when you put it it became we were
making a positive assertion, to me that is distorting words
it is true the underlying cause of mutation (if there is a need for it) is
not fully understood, science admits that.
without a good scientific model to explain mutation, and the observable
spontaneous mutations do not appear to follow a pattern, doesn't it
naturally lead to the temporary conclusion that it can be random?
maybe some day theories will be established ... 阅读全帖
b*******s
发帖数: 954
32
来自主题: Wisdom版 - 没有恒常不变的我
Actually genes change all the time :P
Two examples:
(1) DNA mutates and is repaired in the body all the time.
http://www.ncbi.nlm.nih.gov/books/NBK7566/
"Instability of the human genome: mutation and DNA repair"
A couple quotes from this chapter:
"New mutations arise in single individuals, in somatic cells or in the
germline."
"DNA is also subject to significant spontaneous chemical attack in the
cell. For example, every day approximately 5000 adenines or guanines are
lost from the DNA of each n... 阅读全帖

发帖数: 1
33
◇◇新语丝(www.xys.org)(newxys.com)(xys10.dxiong.com)◇◇
举报南京大学生命学院院长华子春学术不端
方先生您好!
我们反映南京大学生命学院院长、长江、杰青、 国家科技进步奖获得者、
国重主任华子春长期存在学术不端问题。 附件是我们发现的第一批四组共9篇文
章。
1. 2000-C和2000-E两篇文章皆为英文稿, 分布发表于南京大学学报和
Protein Expression and Purification。华教授是通讯作者。 南京大学学报的
内容系于后者的文字上做了删掉,无文字改写。 例如:
前者的第一、二段:
Human cardiac-specific homeobox protein (hCsx2 or Nkx2.5) encodes
a homeobox transcription factor of 323 amino acids containing six
cysteines and is composed of three domains: the TN-domain, the
homeobox- domain, and t... 阅读全帖
c*******e
发帖数: 5818
34
来自主题: Biology版 - Re: 请做遗传学的同学指教
Here I assusme what you ask is simply original reversal mutation, otherwise it
will be complex 'cause the reversal one could be second mutation on the same
gene or totally different gene (mostly tRNA genes). So, We can roughly
estimate it like this. If spontaneous mutation rate is 10 to -6, the chance of
reverse rate could be 10 to -6*2, so it will be 10 to -12. See, very very low.
I guess all the calculation about mutation rate is from bacteria or phage. It
is impossible to use high orgnism, so
t*d
发帖数: 1290
35
来自主题: Biology版 - 一个有趣的基因专利问题
你说得对。
这个官司有趣之处是,microarray 平台和 PCR kit 如果涉及到了这个mutation,就免
不了侵犯了专利,因为你的探针或引物是针对这个mutation位点设计的,利用了专利的
信息。可是 sequencing 同样给出这个mutation 的信息,就不一定侵犯专利。只要
sequencing 的 provider 不主动提供给客户这个mutation 和疾病的关联信息就好了。

.
w*****i
发帖数: 54
36
来自主题: Biology版 - 吵起来了,关于GWAS
我觉得还是一个single gene mutation disease 和complex disease的区别吧。
single gene mutation disease 就是找一个mutation, 一个mutation就可以致病,
犯不着用GWAS
GWAS 本身就是一个association study,用于complex disease才好,大规模样本的
complex disease才好,反正complex disease也没啥好办法研究
w**********9
发帖数: 242
37
来自主题: Biology版 - Harvard stem cell paper retracted
俺觉得这个polyclonal origin 很山寨. 难以置信. 等大牛或教科书改了后俺跟着就是
了.
As of heterogeneity, is this you made up or you got from somewhere ? Did
you ever read Volgestin's work about tumorigenesis in spontaneous colon
cancer ?
=======================================================
3. heterogeneity
As for the heterogeneity of primary tumor, my understanding is that tumor st
arted from one cell that got original mutation and started to divide. When c
ell expanded, some of the cells accumulated other mutations. Alth... 阅读全帖
c**i
发帖数: 6973
38
来自主题: Biology版 - Why Some HIV Carriers Never Develop AIDS
Stephen Smith, Gene research finds clues to AIDS survival; Boston-led study
is part of vaccine search. Boston Globe, Nov. 5, 2010.
http://www.boston.com/news/local/massachusetts/articles/2010/11/05/gene_research_finds_clues_to_aids_survival/
("The genetic testing found something distinctive about that warning system
in controllers — differences in five amino acids, which are the building
blocks of proteins. In those people, a tiny groove in a molecule that is
part of the warning system has a par... 阅读全帖
q*****d
发帖数: 445
39
最近要做library, 使用这个实验室的方法进行易错PCR
http://www.msg.ucsf.edu/agard/Protocols/PCR_Random_Mutagenesis.htm),酶
是NEB的Taq,但是效果一直不是很好,35 cycle PCR的浓度还是很低,30cycle特别的少
,请问
大家有什么方法提高产量吗?还是我的方法不够好,谢谢大家。
PCR Random Mutagenesis
Materials
1. Parental plasmid
2. Oligos surrounding region to be mutagenized
3. Error-prone PCR buffer (10x is 100mM Tris-HCl, pH8.3; 500mM KCl,
70mM MgCl2, 0.1% (w/v) gelatin.)
4. 10mM MnCl2 (stock) (make sure there is no brown coloring to
stock soln; if there is it means... 阅读全帖
j*p
发帖数: 411
40
我也不是很理解,你可以作功能方面的研究,你也可以说,由于这个病人有这个mutation,
改变了他很多gene splicing,从而使的这个病人患上这种疾病.我不觉得这样的story和
统计有什么关系.但是,人家会问,如果这个mutation是造成这种疾病的原因,那么在其他
患相同疾病的患者身上有没有这个mutation?又有多少其他的患者携带这个或者类似紊
乱splicing regulator 的mutation?这就和统计有关了,并且这两个问题显然不能通过
一个病例得到回答.RNA-seq只能帮助你确定gene splicing,并不能帮助你回答这两个问
题.
j*p
发帖数: 411
41
我也不是很理解,你可以作功能方面的研究,你也可以说,由于这个病人有这个mutation,
改变了他很多gene splicing,从而使的这个病人患上这种疾病.我不觉得这样的story和
统计有什么关系.但是,人家会问,如果这个mutation是造成这种疾病的原因,那么在其他
患相同疾病的患者身上有没有这个mutation?又有多少其他的患者携带这个或者类似紊
乱splicing regulator 的mutation?这就和统计有关了,并且这两个问题显然不能通过
一个病例得到回答.RNA-seq只能帮助你确定gene splicing,并不能帮助你回答这两个问
题.
h******y
发帖数: 1374
42
The Nobel Prize in Physiology or Medicine 2011
shall be divided, with one half jointly to
Bruce A. Beutler and Jules A. Hoffmann
for their discoveries concerning the activation of innate immunity
and the other half to
Ralph M. Steinman
for his discovery of the dendritic cell and its role in adaptive immunity
Summary
This year's Nobel Laureates have revolutionized our understanding of the
immune system by discovering key principles for its activation.
Scientists have long been searching for the g... 阅读全帖
l**********1
发帖数: 5204
43
中性随机的漂变 有例外的
尤其是RNA world Eigen model 紫外线灾难的悖论 无法用随机的中性漂变来解释
pls refer
a,
Mutation as a Stress Response and the Regulation of Evolvability
http://www.ncbi.nlm.nih.gov/pubmed/17917874
b,
Evidence That Mutation Is Universally Biased towards AT
in Bacteria
http://www.ncbi.nlm.nih.gov/pubmed/20838599
c
Eigen Model with Correlated Multiple Mutations and Solution of Error
Catastrophe Paradox in the Origin of Life
J. Phys. Soc. Jpn. 81 (2012) 114801
http://jpsj.ipap.jp/link?JPSJ/81/114801
d,
Kirakosyan... 阅读全帖
O******e
发帖数: 4845
44
Severe Congenital Disorder Successfully Treated in a Mouse Model for the
First Time
http://www.sciencedaily.com/releases/2011/12/111222103044.htm
ScienceDaily (Dec. 22, 2011) Using a mouse model, Heidelberg University Ho
spital researchers have for the first time successfully treated a severe con
genital disorder in which sugar metabolism is disturbed. The team headed by
Prof. Christian Korner, group leader at the Center for Child and Adolescent
Medicine, demonstrated that if female mice are giv... 阅读全帖
l**********1
发帖数: 5204
45
LZ为了过份表达 选的promoter inserted xxxxx bases upstream of the Start codon may affect the Kozak
sequence or rbs.
then a nonsense mutation is a mutation that causes a premature stop,
resulting in a truncated or nonfunctional protein
NB: if it is my misunderstood please let me know it.
回复]
>发信人: vonda (Vonda), 信区: Biology
标 题: Re: 用qPCR检测mRNA,高1000倍,却看不到蛋白
发信站: BBS 未名空间站 (Tue Jan 31 19:01:56 2012, 美东)
天……我overexpress的是一个extensively studied的蛋白。。。没有文献报导过它不
稳定。那是阅读框错了?但是overexpress后,细胞的一些signaling pathway... 阅读全帖
o********r
发帖数: 775
46
Then the mutation is called a "germline" mutation, not a "somatic" mutation.
It is impossible to identify driver mutations from bioinformatics alone
using a single patient.
V***b
发帖数: 3419
47
我现在不明白大规模测序之后,拿到一堆数据,和什么去比对?怎样定义“正常组织”
?比如说Steve Jobs的测序结果怎样?如果发现EGFR/PI3K/Ras这些常见突变倒好说(
其实即便这样也很难下定论),最怕就是发现很多突变,却无法将5%,甚至更少的
cancerous mutation,以及各种cancerous mutation组合,从95%的harmless mutation
中分离出来。把Jobs的胰腺癌细胞和他身上正常组织的序列比较,或者跟另一个“健康
人”的序列比较,肯定有非常多的不一样。

mutation.
o********r
发帖数: 775
48
Then the mutation is called a "germline" mutation, not a "somatic" mutation.
It is impossible to identify driver mutations from bioinformatics alone
using a single patient.
V***b
发帖数: 3419
49
我现在不明白大规模测序之后,拿到一堆数据,和什么去比对?怎样定义“正常组织”
?比如说Steve Jobs的测序结果怎样?如果发现EGFR/PI3K/Ras这些常见突变倒好说(
其实即便这样也很难下定论),最怕就是发现很多突变,却无法将5%,甚至更少的
cancerous mutation,以及各种cancerous mutation组合,从95%的harmless mutation
中分离出来。把Jobs的胰腺癌细胞和他身上正常组织的序列比较,或者跟另一个“健康
人”的序列比较,肯定有非常多的不一样。

mutation.
D******9
发帖数: 2665
50
突变五花八样, 大多数蛋白在细胞里, 又没有酶活性。 健康人早点测个序, 假如有
这些突
变,早点做个肠镜才是真的。
Comprehensive molecular characterization of human colon and rectal cancer.
Cancer Genome Atlas Network.
Abstract
To characterize somatic alterations in colorectal carcinoma, we conducted a
genome-scale analysis of 276 samples, analysing exome sequence, DNA copy
number, promoter methylation and messenger RNA and microRNA expression. A
subset of these samples (97) underwent low-depth-of-coverage whole-genome
sequencing. In total, 16% of co... 阅读全帖
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