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2007年8月23日Nature中文摘要
 BIOX.CN  来源：生命经纬    2007年08月23日
封面故事： 细胞间隙连接处探秘
Gap junction adhesion is necessary for radial migration in the
neocortex
间隙连接处（Gap junctions）是相邻细胞形成小孔或通道、让信号分子和离子
在细胞之间自由通过的地方，它们存在于脊椎动物的很多成年细胞和正在发育的
细胞中。它们的功能一直被认为在很大程度是由于细胞之间的分子流动。但事情
并不是这么简单。现在，Elias等人提供的证据表明，间隙连接处在神经迁移中
发挥一定作用，而对迁移来说重要的是间隙连接蛋白的粘附性能及细胞之间接触
点的性质，不是它们通道的导通性能。这一发现的意义已经超出了脑发育。因为
很多其他间隙连接功能（包括参与肿瘤的转移）也可能取决于粘附性能而不是小
孔功能，所以间隙连接处可能因以前没有被考虑到的方式而易于操控。本期封面
所示为沿着脑中的放射状纤维爬行的神经元，而提供粘附接触的一团团间隙连接
处用橙色显示。（Letter p. 901; News & Views）（封面图片：K. X.
Probst）


关于由网格蛋白调控的内吞作用的分子知识（INSIDE STORY）
Integrating molecular and network biology to decode endocytosis
网络生物学的优势在于，它能够在没有先验性的机制方面或分子方面知识的情况
下获得细胞生物学信息。在一项分析中，Eva Schmid 和 Harvey McMahon发现，
从分子水平上来了解网格蛋白（clathrin）调控的内吞作用（Endocytosis）
（被真核细胞用来将营养物和其他分子装进囊泡中进行内部化的过程），可以改
进网络生物学研究方法，使研究人员能够总结出具有普遍性的生物学原理。
（Analysis p. 883）


逐步状态坍缩过程的观测（Count photons with atoms）
Progressive field-state collapse and quantum non-demolition photon
counting
量子测量将一个微观系统置于这样一个状态，在该状态，其所观测到的数量（以
前是不确定的）可以精确知道。其数值是随机的，具有一个由该系统最初状态决
定的概率。这样的“状态坍缩”（state collapse）可以是渐进性的，能够对初
级状态变化的效应进行累积。现在，研究人员利用光作为研究对象，用以非破坏
性方式测量其光子数的一个原子流来不断进行测量，从而观测到了这种类型的逐
步坍缩。这个过程具有量子测量所预测的全部特点，并且应当有助于束缚在空腔
中的非经典电磁场的研究工作。（Article p. 889; News & Views）


SAPAP3与强迫症的关系（OCD in mice）
Cortico-striatal synaptic defects and OCD-like behaviours in
Sapap3-mutant mice
强迫症（obsessive-compulsive disorder）的神经生物学原因基本上不清楚，
尽管“皮质纹状体回路”（corticostriatal circuitry）的破坏受到怀疑。对
很多医学状况来说，小鼠模型都能提供一个进行病理分析和试验潜在治疗方法的
手段。令人吃惊的是，现在对强迫症也能做到这一点了。定向删除SAPAP3（一种
在纹状体中高度表达的突触后支架蛋白）后，小鼠会表现出强迫症的很多行为特
征：它们强迫性地自我修饰，表现焦虑，并有异常的皮质纹状体生理。它们的行
为特征可以被“血清素再吸收抑制剂”减轻，这类药物经常被用来治疗强迫症。
（Article p. 894; News & Views）


南半球冰川形成早于北半球（No need for an icy north）
No extreme bipolar glaciation during the main Eocene calcite
compensation shift
不久前，人们还认为北半球冰川化开始于距今1100万年至500万年前，但这一观
点受到与其相矛盾的证据的挑战，其中包括关于4160万年前超过南极洲存储容量
的全球冰川体积的估计数字。Edgar等人利用来自赤道大西洋的海洋沉积物记录
对认为当时两个半球都存在大型冰层的假设进行了验证。他们关于冰层体积的估
计值可以很容易按照南极洲的存储容量得到解释，这表明，大型冰层那时在北半
球是不存在的。气候模型模拟结果表明，由于两极不同的陆地-海洋分布，大陆
冰川化的临界值在南半球比在北半球更早被突破。本项研究的这些发现支持这样
的模拟结果。（Letter p. 908）


Croll–Milankovitch气候变化理论得到验证（An old theory put to the
test）
Northern Hemisphere forcing of climatic cycles in Antarctica over the
past 360,000 years
Croll–Milankovitch气候变化理论认为，冰期-间冰期周期是由北半球高纬度地
区夏季接收到的日照量的变化决定的，而后者又是由地球轨道几何的变化引起
的。为了验证这一假设，Kawamura等人利用束缚在冰中的空气中的氧分子和氮分
子比例（这个比例能够反映局部地区夏季日照变化，是一个间接指标）构建了关
于南极冰芯的一个新的年谱。结果表明，在过去360,000年，轨道尺度的南极气
候变化滞后于北半球日照的变化，在最后四个冰期-间冰期过渡阶段中，南极温
度的上升发生在北半球夏季日照量增加的阶段。因此，这些发现支持Croll–
Milankovitch假设。（Letter p. 912）


Jack Hills 锆石中发现42.52亿年前金刚石微粒（Calibrating ‘forever’?）
Hadean diamonds in zircon from Jack Hills, Western Australia
来自澳大利亚西部Jack Hills的距今超过40亿年的碎锆石是迄今识别出的最古老
的地壳碎片，在保存关于地球最早演化的信息方面具有独特意义。现在，研究人
员在Jack Hills 锆石中发现了距今42.52亿年前的金刚石微粒包容物，其中包括
在陆地岩石中发现的已知最古老的金刚石。这些材料的年代跨度表明，要么金刚
石形成所需的条件在地球早期历史中重复过几次，要么古老的金刚石经过了显著
的循环。除非早期地球上的条件是独特的，否则这些发现就意味着，至少在距今
42.50亿年前地球大陆岩石圈相对比较厚，而且地壳-地幔之间有相互作用。
（Letter p. 917; News & Views）


从牙齿化石判断大猩猩和黑猩猩-人类之间的分异时间（A farewell to
gorillas）
A new species of great ape from the late Miocene epoch in Ethiopia
确定大猩猩、黑猩猩和人类分异的时间，一直是基本不受化石证据限制的分子系
统发生学的研究范畴。现在，Gen Suwa等人介绍了来自埃塞俄比亚的牙齿化石，
尽管它们距今已经1000万年，但却非常像现代大猩猩的牙齿。如果这些牙齿（被
认为属于一个类人猿新种）来自大猩猩这个分支上的一个动物，那么大猩猩和黑
猩猩-人类之间的分异一定是在这个时间之前发生的，这样便对通过比较现代遗
传序列得到的分异时间施加了限制。（Letter p. 921）


一荣俱荣，一损俱损（All go together when we go）
Non-random coextinctions in phylogenetically structured mutualistic
networks
植物和它们的授粉者及种子扩散者形成相互依赖的复杂网络。这些网络具有强烈
影响生物多样性维护的一个明确架构。Rezende等人利用一种系统发生学方法发
现，植物和动物过去的演化历史部分可以解释该网络的模式。在系统发生学上接
近的物种倾向于在该网络中扮演相似的角色。于是，在一个物种灭绝后发生的一
系列共同灭绝现象会影响在分类上相关的物种，导致演化树发生一种非随机的修
剪。从物种保护角度来讲，这意味着共同灭绝系列事件会在相关物种之间扩散，
进一步加快分类多样性的损失速度。（Letter p. 925; News & Views）


自免疫疾病的分子诱因（Trigger for autoimmunity）
An IRF8-binding promoter variant and AIRE control CHRNA1 promiscuous
expression in thymus
人的胸腺的任务是，教给T-细胞哪些抗原是外来的，哪些是自身的。这个过程在
自免疫疾病中好像是出错了。现在，对在胸腺中表达的一个基因的促进子的变异
所做的一项研究表明，一个核苷酸的变化就可以破坏基因调控，并且还可能导致
自免疫疾病的患病风险增加。这个基因即CHRNA1，为肌肉乙酰胆碱受体的一个亚
单元编码，该亚单元是罕见的神经肌肉疾病——“自免疫重症肌无力”中自免疫
抗体的一个作用目标。（Letter p. 934）


与“安全模式”控制有关的蛋白激酶（PLANT SAFETY）
A central integrator of transcription networks in plant stress and
energy signalling
能够指挥数百种基因的活动、并在如黑暗、杀虫剂处理和洪涝等压力条件下将它
们置于一种“安全模式”的一个控制系统，已在拟南芥中被发现。压力检测和随
后的基因调控是由蛋白激酶KIN10 和 KIN11控制的。这些激酶也见于哺乳动物体
内，在此它们可能同样起能量传感和调控作用。（Letter p. 938）


三种抗郁剂与LueT的结合机制（Antidepressant design）
Antidepressant binding site in a bacterial homologue of
neurotransmitter transporters
三环抗郁剂(tricyclic antidepressants)通过抑制脑中钠耦合的神经传输物质
的输送子来发挥作用，然而关于这些抑制成分在分子层次上是如何工作的我们却
知之甚少。来自喜热细菌Aquifex aeolicus 的LeuT leucine输送子是神经传输
物质的输送子的一个同源物，并且是迄今为止被证明易于进行结构分析的惟一一
个。因此，Singh等人研究了三种抗郁剂——clomipramine、desipramine 和
imipramine——与LueT的结合机制。他们发现，这些药物非竞争性地与一个面向
细胞外的前庭（vestibule）结合，来抑制基质的释放。虽然人脑中的
norepinephrine 和 serotonin受体与LeuT显著不同，但这项工作确定了另一个
也许可用于研制具有治疗潜力的新的抑制剂的区域。（Letter p. 952）


----------------------
NEWS AND VIEWS
----------------------
Neuroscience: Obsessed with grooming pp871 - 872
Roughly 2% of humans suffer from obsessive compulsive disorder, but a
lack of animal models has impeded research into this condition. Could
a genetically engineered mouse model provide an exciting lead?
Steven E. Hyman
doi:10.1038/448871a
http://www.nature.com/nature/journal/v448/n7156/full/448871a.html

Quantum physics: Wave goodbye pp872 - 873
When measuring photons, it's a case of 'wanted, dead' ― catching them
alive is not an option. But we can observe how a superposition of many
photon waves progressively collapses as it interacts with a beam of
atoms.
Luis A. Orozco
doi:10.1038/448872a
http://www.nature.com/nature/journal/v448/n7156/full/448872a.html

50 & 100 Years Ago p873
doi:10.1038/448873a
http://www.nature.com/nature/journal/v448/n7156/full/448873a.html

Economics: Age, health and wealth pp875 - 876
Ageing populations raise the spectre of crippling healthcare costs.
Extra spending on medical research might bring healthier, happier
older people who work (and pay taxes) for longer. Is that a good
investment?
Frances Cairncross
doi:10.1038/448875a
http://www.nature.com/nature/journal/v448/n7156/full/448875a.html

Materials science: Stirring stuff pp876 - 877
Take silicon, soak in water, add acid ― and stir. This simple new
recipe for the self-assembly of complex microstructures belies an
involved sequence of hydrophobic, electrostatic and van der Waals
interactions.
David J. Pine
doi:10.1038/448876a
http://www.nature.com/nature/journal/v448/n7156/full/448876a.html

Evolutionary biology: Structure in mutualistic networks pp877 - 879
Statistical analyses of the networks formed by plant-animal mutualisms
can now take account of the relatedness of the players on either side.
How helpful is this innovation for understanding network dynamics?
Susanne S. Renner
doi:10.1038/448877a
http://www.nature.com/nature/journal/v448/n7156/full/448877a.html

Materials science: Embedded shells decalcified pp879 - 880
Synthetic microcapsules with membrane-bound inner chambers in which
chemical reactions can be isolated and controlled have been assembled,
layer by layer. Could artificial cells be on the horizon?
Catherine Picart and Dennis E. Discher
doi:10.1038/448879a
http://www.nature.com/nature/journal/v448/n7156/full/448879a.html

Earth science: Old diamonds and the upper crust pp880 - 881
Was the early Earth a blackened landscape of congealed lava, or was it
cool enough for oceans to form? The discovery of diamonds in the
oldest-known relics of surface rocks adds new elan to this debate.
Ian S. Williams
doi:10.1038/448880a
http://www.nature.com/nature/journal/v448/n7156/full/448880a.html

Obituary: Daniel Koshland (1920-2007) p882
Biochemist, institution-builder and editor of Science.
Bruce Alberts
doi:10.1038/448882a
http://www.nature.com/nature/journal/v448/n7156/full/448882a.html

----------------------
ANALYSIS
----------------------
Integrating molecular and network biology to decode endocytosis pp883
- 888
The strength of network biology lies in its ability to derive cell
biological information without a priori mechanistic or molecular
knowledge. It is demonstrated that a molecular understanding of
clathrin-mediated endocytosis can refine the network approach and
allows the derivation of general biological principles.
Eva M. Schmid and Harvey T. McMahon
doi:10.1038/nature06031
Abstract:
http://www.nature.com/nature/journal/v448/n7156/abs/nature06031.html
Article:
http://www.nature.com/nature/journal/v448/n7156/full/nature06031.html

----------------------
ARTICLES
----------------------
Progressive field-state collapse and quantum non-demolition photon
counting pp889 - 893
This paper reports the observation of a step-by-step state collapse by
using atoms to non-destructively measure the photon number of a field
stored in a cavity. The procedure illustrates all the postulates of
quantum measurement and should facilitate studies of non-classical
fields trapped in cavities.
Christine Guerlin et al.
doi:10.1038/nature06057
Abstract:
http://www.nature.com/nature/journal/v448/n7156/abs/nature06057.html
Article:
http://www.nature.com/nature/journal/v448/n7156/full/nature06057.html

Cortico-striatal synaptic defects and OCD-like behaviours in
Sapap3-mutant mice pp894 - 900
Targeted deletion of SAPAP3, a postsynaptic scaffolding protein
expressed in the striatum, yields a behavioral phenotype with many
characteristics of obsessive compulsive disorder (OCD). SAPAP3-/- mice
compulsively overgroom themselves and are unusually anxious.
Behavioral symptoms are alleviated by SSRIs, and both behaviour and
physiological abnormalities are rescued by lentiviral-mediated
expression of SAPAP3 in the striatum.
Jeffrey M. Welch et al.
doi:10.1038/nature06104
Abstract:
http://www.nature.com/nature/journal/v448/n7156/abs/nature06104.html
Article:
http://www.nature.com/nature/journal/v448/n7156/full/nature06104.html

Gap junction adhesion is necessary for radial migration in the
neocortex pp901 - 907
This paper describes the first evidence of a role for gap junctions in
neuronal migration, and also shows that the adhesive properties of the
gap junctions, not the conductivity of their channels, are important
for the migration.
Laura A. B. Elias, Doris D. Wang and Arnold R. Kriegstein
doi:10.1038/nature06063
Abstract:
http://www.nature.com/nature/journal/v448/n7156/abs/nature06063.html
Article:
http://www.nature.com/nature/journal/v448/n7156/full/nature06063.html

----------------------
LETTERS
----------------------
No extreme bipolar glaciation during the main Eocene calcite
compensation shift pp908 - 911
The hypothesis that large ice sheets were present in both hemispheres
～41.6 million years ago is tested, using marine sediment records from
the equatorial Atlantic Ocean. The estimates of ice volume at this
time can easily be accommodated on Antarctica, but were not the
Northern Hemisphere. These findings support climate model simulations,
which indicate that the threshold for continental glaciation was
crossed earlier in the Southern Hemisphere than in the Northern
Hemisphere, due to the different land-ocean distributions at the two
poles.
Kirsty M. Edgar, Paul A. Wilson, Philip F. Sexton and Yusuke Suganuma
doi:10.1038/nature06053
Abstract:
http://www.nature.com/nature/journal/v448/n7156/abs/nature06053.html
Article:
http://www.nature.com/nature/journal/v448/n7156/full/nature06053.html

Northern Hemisphere forcing of climatic cycles in Antarctica over the
past 360,000 years pp912 - 916
A new chronology for Antarctic ice cores has been constructed based on
the ratio of oxygen to nitrogen molecules in air trapped in the ice.
This seems to reflect changes in local summer insolation, and thus
allows the relative timing of changes in insolation and Antarctic
climate to be determined. The results show that orbital-scale
Antarctic climate change lagged Northern Hemisphere insolation over
the past 360,000 years, and that increases in Antarctic temperature at
the last four glacial-interglacial transitions took place within
phases of increasing Northern Hemisphere insolation.
Kenji Kawamura et al.
doi:10.1038/nature06015
Abstract:
http://www.nature.com/nature/journal/v448/n7156/abs/nature06015.html
Article:
http://www.nature.com/nature/journal/v448/n7156/full/nature06015.html

Hadean diamonds in zircon from Jack Hills, Western Australia pp917
- 920
This paper reports the discovery of micro-diamond inclusions in zircon
from the Jack Hills (Western Australia), which is up to 4,252 million
years old and includes the oldest known diamonds found in terrestrial
rocks. The spread of ages indicates that either the conditions
required for diamond formation were repeated several times during
early Earth history or that there was significant recycling of ancient
diamond.
Martina Menneken et al.
doi:10.1038/nature06083
Abstract:
http://www.nature.com/nature/journal/v448/n7156/abs/nature06083.html
Article:
http://www.nature.com/nature/journal/v448/n7156/full/nature06083.html

A new species of great ape from the late Miocene epoch in
Ethiopia pp921 - 924
Fossil teeth from Ethiopia are presented that look very similar to
those of a modern gorilla, despite being 10 million years old. If the
teeth, assigned to a new species of fossil ape, come from a creature
on the gorilla lineage, then the divergence between gorillas and the
chimp-human stock must have happened before that time, constraining
divergence dates reached through the comparison of contemporary
genetic sequences.
Gen Suwa et al.
doi:10.1038/nature06113
Abstract:
http://www.nature.com/nature/journal/v448/n7156/abs/nature06113.html
Article:
http://www.nature.com/nature/journal/v448/n7156/full/nature06113.html

Non-random coextinctions in phylogenetically structured mutualistic
networks pp925 - 928
A phylogenetic approach is used to show that past evolutionary history
partly explains network patterns that link plants and their
pollinators and seed dispersers. Species close in the phylogeny tend
to play similar roles in the network. As a result, co-extinction
cascades following the extinction of a species affect taxonomically
related species, resulting in a non-random pruning of the evolutionary
tree.
Enrico L. Rezende et al.
doi:10.1038/nature05956
Abstract:
http://www.nature.com/nature/journal/v448/n7156/abs/nature05956.html
Article:
http://www.nature.com/nature/journal/v448/n7156/full/nature05956.html

Regulation of IgA production by naturally occurring TNF/iNOS-producing
dendritic cells pp929 - 933
Immunoglobulin-A (IgA) is the main immunoglobulin found in mucous
sectretions. B cell class-switch recombination to IgA in
mucosa-associated tissues is regulated by a subset of dendritic cells
which produce TNF-α and inducible nitric oxide in response to the
recognition of commensal bacteria by toll-like receptors
Hiroyuki Tezuka et al.
doi:10.1038/nature06033
Abstract:
http://www.nature.com/nature/journal/v448/n7156/abs/nature06033.html
Article:
http://www.nature.com/nature/journal/v448/n7156/full/nature06033.html

An IRF8-binding promoter variant and AIRE control CHRNA1 promiscuous
expression in thymus pp934 - 937
The human thymus is given the difficult task of teaching T-cells which
antigens are 'foreign' and which are 'self', a process which seems to
go wrong in autoimmune disorders. A study of variation in the promoter
of one gene expressed in thymus shows that one nucleotide change can
disrupt gene regulation, and might lead to increased risk for
autoimmune disease.
Matthieu Giraud et al.
doi:10.1038/nature06066
Abstract:
http://www.nature.com/nature/journal/v448/n7156/abs/nature06066.html
Article:
http://www.nature.com/nature/journal/v448/n7156/full/nature06066.html

A central integrator of transcription networks in plant stress and
energy signalling pp938 - 942
In Arabidopsis thaliana, the evolutionary conserved protein kinases
KIN10 and KIN11, control reprogramming of transcription factors in
response to seemingly unrelated conditions such as darkness, sugar and
stress conditions. Hence KIN10 and KIN11 are key players in linking a
variety of stress conditions in plants and globally regulate plant
metabolism and survival.
Elena Baena-Gonzalez, Filip Rolland, Johan M. Thevelein and Jen Sheen
doi:10.1038/nature06069
Abstract:
http://www.nature.com/nature/journal/v448/n7156/abs/nature06069.html
Article:
http://www.nature.com/nature/journal/v448/n7156/full/nature06069.html

p15Ink4b is a critical tumour suppressor in the absence of
p16Ink4a pp943 - 946
A locus on chromosome 9p21 which encodes three cell cycle inhibitors
is frequently deleted in human cancer. Two of these, p16INKa and
p14ARF, function as tumour suppressors. A new mouse model now shows
that a third, p15INK4b, also contributes to the tumour suppressor
function of this locus. Mice lacking all three show enhanced
tumourigenesis and a broader tumour spectrum.
Paul Krimpenfort et al.
doi:10.1038/nature06084
Abstract:
http://www.nature.com/nature/journal/v448/n7156/abs/nature06084.html
Article:
http://www.nature.com/nature/journal/v448/n7156/full/nature06084.html

The effects of molecular noise and size control on variability in the
budding yeast cell cycle pp947 - 951
Reports on single cell experiments in budding yeast that analyse the
role of molecular noise during the G1 phase of the cell cycle.
Variability in the timing of G1 can be attributed to variations in
cell size at cell birth, as well as variations of a size-independent
'timer' step. These two steps are modular and together control the
timing of the critical Start transition of the G1 phase.
Stefano Di Talia et al.
doi:10.1038/nature06072
Abstract:
http://www.nature.com/nature/journal/v448/n7156/abs/nature06072.html
Article:
http://www.nature.com/nature/journal/v448/n7156/full/nature06072.html

Antidepressant binding site in a bacterial homologue of
neurotransmitter transporters pp952 - 956
The mechanism underlying inhibition of sodium-coupled neurotransmitter
transporters by tricyclic antidepressants (TCAs) is investigated, and
it is found that TCAs bind noncompetitively to an extracellular facing
vestibule to inhibit the release of substrate.
Satinder K. Singh, Atsuko Yamashita and Eric Gouaux
doi:10.1038/nature06038
Abstract:
http://www.nature.com/nature/journal/v448/n7156/abs/nature06038.html
Article:
http://www.nature.com/nature/journal/v448/n7156/full/nature06038.html

 
    
 


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