j**h
发帖数: 126 | 1 nature.com
Sitemap
Register
Login
Nature
International weekly journal of science
Show searchMenu
Archive
Volume 544
Issue 7648
News
Article
NATURE | NEWS
Sharing
Compass protein attracts heap of criticism
Debate grows over a molecule implicated in animal navigation.
David Cyranoski
04 April 2017
Article tools
PDF
Rights & Permissions
George Grall/NGC
The red-spotted newt and many other animals can somehow sense Earth’s
magnetic field.
For decades, scientists have wondered how animals can navigate huge
distances using the weak signals of Earth’s magnetic field. So, interest
was piqued in 2015 when two teams released papers in quick succession
describing the functions of a protein found in animals that seemed to sense
magnetic fields. But the claims have proved controversial, and questions
have been piling up.
The basic science behind the discovery was reported by Xie Can, a
biophysicist at Peking University in Beijing, and his colleagues. In a paper
in Nature Materials1, they claimed that a protein in animal cells
forms a structure that responds to magnetic fields, and so might help in
navigation. In the same year, a group led by Zhang Sheng-jia, then at
Tsinghua University in Beijing, had published a paper in Science
Bulletin2 reporting that the same protein could offer a powerful means
of controlling brain cells.
An academic battle has long raged between Xie and Zhang, but mounting
evidence has cast doubt on both of their discoveries. Several researchers
have challenged Xie’s claims that the protein reacts to magnetic fields.
And last month, Xie co-authored a paper in Frontiers in Neural
Circuits3 disputing Zhang’s work on the protein’s potential to
magnetically control cells.
Related stories
Discovery of long-sought biological compass claimed
Neuroscientist fired after dispute over magnetic-protein research
Chinese scientists row over long-sought protein that senses magnetism
This has all given rise to serious questions about the role of the molecule
at the centre of the dispute. In their 2015 paper1, Xie and his colleagues
reported that a protein called IscA1 forms a complex with another protein,
Cry4, that explains how organisms pick up magnetic cues. The study found
that this complex incorporates iron atoms, which gives it magnetic
properties, and has a rod-like shape that aligns with an applied magnetic
field.
Two months earlier, Zhang had described using IscA1 to control neurons and
muscle cells in worms2. Zhang learned of IscA1’s properties and obtained
his IscA1 samples from Xie, and so the fact that his team published first
was an early source of tension in what quickly became a bitter dispute.
Officials from both Tsinghua University and Peking University asked
Science Bulletin to retract Zhang’s paper. And that November, Zhang&#
160;lost his position at Tsinghua — for reasons that the university
did not specify.
“The data are what they are. This may expand our knowledge of molecular
magnets.”
Doubts about Xie’s research have emerged since then. Michael Winklhofer, a
geophysicist at the University of Oldenburg in Germany, examined Xie’s data
and found that the complex would be too weakly magnetic to sense Earth’s
field4. Markus Meister, a biophysicist at the California Institute of
Technology in Pasadena, raised similar concerns: Xie had reported that the
complex would contain only 40 iron atoms, but Meister argues that the
smallest known naturally occurring iron-based magnet has 1 million iron
atoms packed into a smaller space5.
David Keays, a neuroscientist at the Institute of Molecular Pathology in
Vienna, has also questioned the study. He says that IscA1 and Cry4 are found
throughout many tissues, whereas one would expect them to be sequestered in
specific areas if they were functioning as parts of a magnetic-field
receptor. “Sensory receptors, whether they be taste, hearing or photo-
receptors, tend to have a restricted expression pattern,” he says.
Collaborators of Xie say that they have been able to reproduce some of his
findings, and Xie told Nature that he stands by his results. He
disputes the contention that the magnetic properties of IscA1 would be too
weak by saying that Cry4 might boost its effect. “The data are what they
are,” he says. “This may expand our knowledge of molecular magnets.”
The challenge to Zhang’s paper has been more pointed. Zhang claimed to have
transferred IscA1 into worm neurons and then used a magnetic field to
induce the cells to take up calcium. The ability to manipulate such a basic
cell function could promise neuroscientists a powerful tool that is less
invasive than opto-genetic techniques, which use light-sensitive proteins to
control neurons in living animals.
But last month, Xie, Tsinghua University neuroscientist Lu Bai and Lu’s
student Pang Keliang reported3 carrying out experiments under various
conditions, including some almost identical to those used by Zhang. They
found no change in calcium flowing into cells in any of the cases. The
authors conclude that the “findings cast serious doubts” that IscA1 alone
could influence the activity of neurons, as Zhang had claimed.
Several scientists outside China also told Nature that they could
not reproduce Zhang’s results. Nature tried to reach Zhang
through multiple e-mails and phone calls to Shenzhen University in China,
where he now has a position, but he did not respond to requests for comment.
(Neither Nature Materials, which is editorially independent from
Nature’s news team, nor Science Bulletin responded to requests
for comment about criticism of the papers.)
Meanwhile, even as his critics become increasingly aggressive, Xie says he
has convincing data that demonstrate the reaction of an IscA1 complex to a
magnetic field, and that he plans to publish them within a year. “We are
more and more confident — 100% sure — that we are right about this,” he
says.
Nature
544, 16–17 (06 April 2017)doi:10.1038/544016a
Tweet Follow @NatureNews
References
Qin, S. et al. Nature Mater. 15, 217–226 (2016).
Article
PubMed
ChemPort
Show context
Long, X., Ye, J. & Zhang, S-J. Sci. Bull. 60,
2107–2119 (2015).
Article
ChemPort
Show context
Pang, K. et al. Front. Neural Circuitshttp://dx.doi.org/10.3389/fncir.2017.00011 (2017).
Show context
Winklhofer, M. & Mouritsen, H. Preprint at bioRxiv http://dx.doi.org/10.1101/094607 (2016).
Show context
Meister, M. eLife 5, e17210 (2016).
Article
PubMed
Show context
Related stories and links
From nature.com
Discovery of long-sought biological compass claimed
16 November 2015
Neuroscientist fired after dispute over magnetic-protein research
05 November 2015
Chinese scientists row over long-sought protein that senses magnetism
21 September 2015
Author information
For the best commenting experience, please login or register as a user&
#160;and agree to our Community Guidelines. You will be re-directed
back to this page where you will see comments updating in real-time and have
the ability to recommend comments to other users.
Comments
CommentsSubscribe to comments
There are currently no comments.
See other News & Comment articles from Nature
Japanese scientists call for boycott of military research
CRISPR studies muddy results of older gene research
Migration: Refugee economics
Medical history: A surgeon for all seasons
Energy: Muscle, steam and combustion
Philanthropy: The politics of giving
Meteorology: Weather makers
Physics: Revelations of fundamental science
New in Paperback
Brazilian budget woes, negative results and botany in the digital era
Smart manufacturing must embrace big data
How the genomics revolution could finally help Africa
Machine learning predicts the look of stem cells
‘Young poo’ makes aged fish live longer
Label the limits of forensic science
Ancient DNA and the rise of ‘celebrity science’
Compass protein attracts heap of criticism
Hunt for cancer 'tipping point' heats up
Brazilian scientists reeling as federal funds slashed by nearly half
Genetic details of controversial 'three-parent baby' revealed
Scroll left
Scroll right
Social Media Box - AML
E-alert
RSS
Facebook
Twitter
Sea monsters
How giant marine reptiles terrorized the ancient seas
Ichthyosaurs were some of the largest and most mysterious predators to ever
prowl the oceans. Now they are giving up their secrets.
Top Content - Article Page
Recent
Japanese scientists call for boycott of military research
Nature 06 April 2017
CRISPR studies muddy results of older gene research
Nature 05 April 2017
Migration: Refugee economics
Nature 05 April 2017
Read
Commented
Newsletter
The best science news from Nature and beyond, direct to your inbox
every day.
Pre-cancer genome
Hunt for cancer 'tipping point' heats up
'Pre-cancer' genome atlas proposed to track tumours as they turn
from benign to dangerous.
What does Brexit mean for working scientists?
How Brexit is changing the lives of eight researchers
The months between the Brexit vote and this week's triggering of Article
50 have been a turbulent time for scientists — and things show no sign of
calming.
Rigour, reproducibility, robustness
Remember why we work on cancer
Levi Garraway reflects on the three things that keep his compass true when
the going gets tough.
iPS cell donation
Pioneering cell transplant shows vision and promise
Japan deserves praise for early success, but must still exercise caution in
commercializing induced pluripotent stem-cell treatments.
Nature Podcast
Listen
This week, mapping sound in the brain, dwindling groundwater, and giving
common iron uncommon properties.
Science jobs from naturejobs
Faculty Position for Research Director of the Animal BSL3 Facility at Duke-
NUS
DUKE-NUS Medical school
Ph.D. Program and Integrated MS-Ph.D. Program of IBS School-UST
Institute for Basic Science
Chief of Newborn Medicine
Mass General for Chil | s******y
发帖数: 17729 | 2 抢屎，这下连锅都砸了，屎泼出来，俩个头上都得浇上
【在 j**h 的大作中提到】
: nature.com
: Sitemap
: Register
: Login
: Nature
: International weekly journal of science
: Show searchMenu
: Archive
: Volume 544
: Issue 7648
| j******i
发帖数: 939 | 3 转BioArt
4月4日，Nature在线发布了一篇题为“Compass protein attracts heap of criticism
”的新闻报道（News），文章直指磁受体蛋白相关研究目前面临的巨大争议。
2015年11月16日，北京大学生科院谢灿课题组在Nature Materials杂志在线发表论文，
声称首次报道了一个全新的磁受体蛋白（MagR），当时众多媒体报道该突破性进展或将
揭开被称为生物“第六感”的磁觉之谜，并推动整个生物磁感受能力研究领域的发展。
值得一提的是，该成果还获得2015年度“中国生命科学十大进展”。与此同时，当时还
在清华大学的张生家课题组2015年9月14日在Science Bulletin（科学通报）发表论文
声称利用Isca1（MagR）蛋白开发出了一种磁遗传学工具（磁场诱发神经元的相关活动
）。
诚然，此后围绕磁受体蛋白或者磁遗传的引发了一次中国学术史上罕见的争论，至今尚
未平息，BioArt这里不再赘述。回到Nature刚刚发布的报道，文中提及了今年3月16日
，来自清华大学医学院鲁白实验室联合北京大学生科院谢灿实验室在Frontiers in
Neural Circuits杂志上在线发表了一篇论文表明，磁感应蛋白MagR在HEK293T细胞、海
马体神经元细胞和背根神经节细胞（DRGN）中分别表达MagR后并不能对磁场刺激产生反
应，也没有钙离子信号的变化（下图），也就是说该文的结论正好与张生家课题组此前
发表在Science Bulletin上的文章的结论相反。
除去这些国内的系列争端，有关磁感应蛋白在国际范围内也受到了诸多质疑，其中比较
有代表性的是2016年8月16日，加州理工学院的Markus Meister在eLife杂志上发表了一
篇题为“Physical limits to magnetogenetics”的文章，文章针对过去一段时间发表
的几篇有关“磁遗传学”文章展开讨论（注：该文没有引用张生家此前在Science
Bulletin上发表的文章），并用物理学定律对这些报道进行了质疑和探讨。该文的主要
意思大致是说：谢灿组发现那个MagR蛋白复合体里面铁原子太少，不可能产生磁矩。
Nature的报道里称，MagR蛋白复合体只有40个铁原子，而自然条件下发生基于铁离子的
磁场反需要100万个铁原子包裹在一个小空间里（Xie had reported that the complex
would contain only 40 iron atoms, but Meister argues that the smallest
known naturally occurring iron-based magnet has 1 million iron atoms packed
into a smaller space）。另外那几个改造离子通道的meganetogenetics tools（发表
在Nature Medcine、Nature Neuroscience杂志上的成果）也不可能产生足够的力驱使
蛋白构像变化。
该预印本论文主要的质疑的内容有两点。第一，谢灿研究组在2015年的论文中并没有提
供证据显示ISCA1（MagR）和光受体CRY4蛋白在体内有直接相互作用（注：谢灿组的
Nature Materials论文中有使用免疫组织化学实验证明了磁感应受体MagR蛋白质和光受
体Cry蛋白质在鸽子视网膜存在共定位）；第二，谢灿组实验中所用的CRY4蛋白的序列
有误，非正确的完整序列（注：Nature Materials论文中CRY4的序列中包含497个氨基
酸而预印本中显示全场应为525aa-鸽子）、529aa-鸡、527aa-斑马鱼）。
此外，印本论文主中的实验结果表明ISCA1（MagR）和CRY4在多种组织中广泛表达，并
不具备组织特异性（下图），而作为磁受体来讲，一般认为这种蛋白应该具有组织特异
性表达。
针对上述质疑，谢灿及其合作者在给Nature的回复中表示道，他们也能重复上述部分结
果，然而数据就在那，或许这项研究（指Nature Materials论文）拓展了我们对现有分
子磁体的认知（Collaborators of Xie say that they have been able to reproduce
some of his findings, and Xie told Nature that he stands by his results. He
disputes the contention that the magnetic properties of IscA1 would be too
weak by saying that Cry4 might boost its effect. “The data are what they
are,” he says. “This may expand our knowledge of molecular magnets.”）。
此外，谢灿也向Nature表示了即便如今面临了诸多争议，但是他百分百确信自己团队的
研究（“We are more and more confident — 100% sure — that we are right
about this”），他所在的团队还计划在一年内发表相关文章证明ISCA1蛋白复合体在
磁场下的反应。
Nature的报道中还提到，一些中国以外的科学家告诉Nature，表示他们并不能重复张生
家此前的实验结果。Nature也试图通过邮件和电话联系张生家及其目前所在的单位深圳
大学，但是都没有得到回复。 | w********m
发帖数: 1137 | | f*****8
发帖数: 2977 | 5 浪费民脂民膏
criticism
【在 j******i 的大作中提到】
: 转BioArt
: 4月4日，Nature在线发布了一篇题为“Compass protein attracts heap of criticism
: ”的新闻报道（News），文章直指磁受体蛋白相关研究目前面临的巨大争议。
: 2015年11月16日，北京大学生科院谢灿课题组在Nature Materials杂志在线发表论文，
: 声称首次报道了一个全新的磁受体蛋白（MagR），当时众多媒体报道该突破性进展或将
: 揭开被称为生物“第六感”的磁觉之谜，并推动整个生物磁感受能力研究领域的发展。
: 值得一提的是，该成果还获得2015年度“中国生命科学十大进展”。与此同时，当时还
: 在清华大学的张生家课题组2015年9月14日在Science Bulletin（科学通报）发表论文
: 声称利用Isca1（MagR）蛋白开发出了一种磁遗传学工具（磁场诱发神经元的相关活动
: ）。
| j*********g
发帖数: 463 | 6 谢灿也是因祸得福，如果不是张生家那么一闹，他成了受害者，也不可能在北大tenure。
谢灿5年，花掉国家1000万人民币，10个学生的青春和时间，就做了这么个半真半假的
破玩意，真是匪夷所思。他本来也不是搞磁生物学的，不是做结构的么。他是不是想出
名想疯了，全部资源都投在这个课题了，擅长的结构不做？5年只做了这一个课题？别
的都没成？ | z*******o
发帖数: 1794 | 7 套用一句话：“贵圈真乱！”
【在 j**h 的大作中提到】
: nature.com
: Sitemap
: Register
: Login
: Nature
: International weekly journal of science
: Show searchMenu
: Archive
: Volume 544
: Issue 7648
| s******y
发帖数: 17729 | 8 现在哪还分做啥的，全都一窝蜂的上灌水，灌大水，能出CNS就把学生和钱毫不犹豫的砸
下去。
tenure。
【在 j*********g 的大作中提到】
: 谢灿也是因祸得福，如果不是张生家那么一闹，他成了受害者，也不可能在北大tenure。
: 谢灿5年，花掉国家1000万人民币，10个学生的青春和时间，就做了这么个半真半假的
: 破玩意，真是匪夷所思。他本来也不是搞磁生物学的，不是做结构的么。他是不是想出
: 名想疯了，全部资源都投在这个课题了，擅长的结构不做？5年只做了这一个课题？别
: 的都没成？
| c********6
发帖数: 693 | | c**********n
发帖数: 177 | | | | b*****n
发帖数: 128 | 11 有些喜欢过把瘾，有人喜欢细水长流，top 大学里混，不是大牛不赌几把怎么立足， | b*****n
发帖数: 128 | 12 烧点钱算什么，整个人类历史，烧了多少钱，能出结果的有几个？ | b*****n
发帖数: 128 | | C*****l
发帖数: 3211 | 14 不知道搞磁蛋白的能不能写出麦克斯韦方程。
lol
【在 c**********n 的大作中提到】
: 不懂数理真坑爹。。
| s******e
发帖数: 163 | 15 谢灿不是CLS的，估计没花1000万，CLS都是1000万 | C***3
发帖数: 1719 | 16 这个角度不错
【在 b*****n 的大作中提到】
: 长城磊了那么久，还不是一片废墟
| c****3
发帖数: 10787 | 17 城市里鸽子回家，会受到手机基站信号干扰，明摆着就不是指南针，而是更复杂的东西。
指南针怎么可能被高频无线信号干扰。 | c****3
发帖数: 10787 | 18 地磁场是个静止磁场，也可能是很低的频率，而且很小电磁辐射。手机基站频率，最低
也有900MHz。
鸽子被基站信号干扰，回家迷路，说明鸽子在接受电磁辐射信号，需要靠此定位，具体
是那里的电磁辐射，太阳的，还是大气层的反射，就不知道了。
这是很容易通过现象判断的，只要有点电磁学的经验。
鸽子没有电磁辐射接受装置，是不会被干扰的。指南针只是根据静止磁场定位，算不上
电磁辐射接受装置。 | C*****l
发帖数: 3211 | 19 鸽子的脑子里某种蛋白是谐振腔？
用各个频段微波鸽子。好残忍。。
【在 c****3 的大作中提到】
: 地磁场是个静止磁场，也可能是很低的频率，而且很小电磁辐射。手机基站频率，最低
: 也有900MHz。
: 鸽子被基站信号干扰，回家迷路，说明鸽子在接受电磁辐射信号，需要靠此定位，具体
: 是那里的电磁辐射，太阳的，还是大气层的反射，就不知道了。
: 这是很容易通过现象判断的，只要有点电磁学的经验。
: 鸽子没有电磁辐射接受装置，是不会被干扰的。指南针只是根据静止磁场定位，算不上
: 电磁辐射接受装置。
| c****3
发帖数: 10787 | 20 谢灿需要补课电磁学知识，这样一开始就不会认为是指南针了。
如果是电磁信号接受装置，所有质疑都有合理解释了。在鸽子大脑里找天线，放大器，
滤波器，对他只好不坏。
【在 C*****l 的大作中提到】
: 鸽子的脑子里某种蛋白是谐振腔？
: 用各个频段微波鸽子。好残忍。。
| | | m****a
发帖数: 270 | 21 瞎扯。影响鸽子的是广场大喇叭，不是基站信号。
西。
【在 c****3 的大作中提到】
: 城市里鸽子回家，会受到手机基站信号干扰，明摆着就不是指南针，而是更复杂的东西。
: 指南针怎么可能被高频无线信号干扰。
| c****3
发帖数: 10787 | 22 http://www.saige.com/news/a251282.htm
【在 m****a 的大作中提到】
: 瞎扯。影响鸽子的是广场大喇叭，不是基站信号。
:
: 西。
| P****R
发帖数: 22479 | 23 神经本身就是一个生物电系统，也会有电磁感应。
【在 c****3 的大作中提到】
: 地磁场是个静止磁场，也可能是很低的频率，而且很小电磁辐射。手机基站频率，最低
: 也有900MHz。
: 鸽子被基站信号干扰，回家迷路，说明鸽子在接受电磁辐射信号，需要靠此定位，具体
: 是那里的电磁辐射，太阳的，还是大气层的反射，就不知道了。
: 这是很容易通过现象判断的，只要有点电磁学的经验。
: 鸽子没有电磁辐射接受装置，是不会被干扰的。指南针只是根据静止磁场定位，算不上
: 电磁辐射接受装置。
| c****3
发帖数: 10787 | 24 这种极其微弱电流，影响不了生物正常工作的。你把小白老鼠，放到基站下面，它的生
理功能也不会被影响，可能长期对细胞寿命有影响。
鸽子导航被影响，肯定是在主动接受电磁波，很可能是太阳直射的，或者通过大气层反
射的。所以天气不好鸽子导航会受影响，因为高频电磁波收到天气影响大，GPS和卫星
电视天气不好，也常常工作不好
【在 P****R 的大作中提到】
: 神经本身就是一个生物电系统，也会有电磁感应。
| g*****n
发帖数: 250 | 25 地球的磁场是动态的，每年都有变化。而且有区域性小磁场。动物用其导航很不稳定。
大磁场南北两极会调换。在4万年前有过非完全反转，78万年前有过完全反转。动物若
用其导航，就必须快速进化来适应磁场的变化。 |
|
