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2007年9月27日Nature中文摘要
 BIOX.CN  来源：生命经纬    2007年09月27日
封面故事：超导量子位之间的信息传输与交换
Coherent quantum state storage and transfer between two phase qubits
via a resonant cavity / Coupling superconducting qubits via a cavity
bus
用微制造方法制造的超导电路元件，能够利用量子行为进行信息处理。与经典信
息位不同的是，量子信息位（qubits）能形成所谓的“超级位置”，即由ON 和
OFF组成的混合状态，从而能提供更快的、自然形式的并行处理。以前，研究人
员已经实现了多达4个量子位的直接量子位-量子位耦合，但现在两个独立小组演
示了下一个关键步骤：两个超导量子位置之间通过一个量子母线进行的量子信息
通信和交换，而这个量子母线是以由一根几毫米长的超导传输线形成的一个共振
腔的形式存在的。利用这一微波腔，就有可能在两个量子位之间存储、传输和交
换量子信息。它还能进行多路复用量子位读出。这种基础架构本身可以扩展，从
而为大量超导量子位之间的相干互动提供了可能性。本期封面所示为一个长的之
字形共振腔或量子母线，它连接着两个小的超导相量子位。（Letters pp. 438,
443）封面美术：Jack Bertram, Motion Forge, Inc for Sillanpaa et al。


树状细胞与免疫反应的关系（Cells with connections）
Taking dendritic cells into medicine
树状细胞存在于血液和暴露于环境中的组织中，如皮肤和鼻子、肺、胃和小肠的
上皮组织。它们的作用是调节对当前环境刺激的先天和后天免疫反应。在一篇
Review文章中，Ralph Steinman 和 Jacques Banchereau讨论了树状细胞具有医
学意义的性质。病原体和肿瘤能够利用树状细胞来逃避免疫，从而使它们成为进
行药物治疗的逻辑目标。但它们还能产生抵抗力。在过敏、自免疫和对移植器官
的抵抗过程中，树状细胞可能会激发我们不想要的反应，但这种反应也可以加以
利用，来抑制这些状况。（Review Article p. 419）


从臼齿排列看发育与演化之间的关系（Evolutionary options）
Predicting evolutionary patterns of mammalian teeth from development
现在已经清楚的一个事实是，生态是决定生命多样性中的一个主要因素。但发育
中是否还有引导演化的因素？“演化-发育”（Evo-devo）研究的目标是，通过
考查不同动物和植物相对于我们所了解的它们的祖先关系的发育过程来回答这个
问题。小鼠臼齿的排列是对发育与演化之间联系的一个有效检验。第一颗臼齿大
于它后面的一颗，而后面这颗又大于第三颗、即最靠后的一颗。Kavanagh等人通
过实验对此进行了研究，发现臼齿发育遵守一种抑制性级联模式。结果表明，虽
然饮食一直是牙齿演化中的驱动因素，但发育能够产生可供自然选择过程利用的
选择项目。对于常给我们带来麻烦的智齿而言，其之所以有麻烦，原因可能是我
们的抑制性级联比较弱。（Article p. 427）


一种能将尿嘧啶从DNA中除去的酶“警察”（Keeping DNA non-U）
Enzymatic capture of an extrahelical thymine in the search for uracil
in DNA
尿嘧啶属于RNA，它在其中的位置跟胸腺嘧啶在DNA中的位置是一样的。但如果尿
嘧啶错误地出现在DNA中，它会导致潜在有生命危险的突变。这种情况一般会因
胞嘧啶的化学改变而出现。为了防止这种威胁，细胞会利用一种酶（被称为“尿
嘧啶DNA糖基酶”，简称UNG）来将尿嘧啶从DNA中除去。这种酶保护DNA不受“误
入歧途”的尿嘧啶威胁的详细机制现在已经被揭示出来。DNA螺旋不是静止的，
而是处在一种非常像分子“呼吸”的过程中，碱基对短暂分开和重新形成。当一
个尿嘧啶碱基出现时，它会被“尿嘧啶DNA糖基酶”从螺旋中抓出来，并除掉。
与尿嘧啶只有一个甲基差别的胸腺嘧啶同样也会被抓住，但由于它并不是非常适
合这种充当“警察”的酶的活性点，所以它会被释放，去做其在DNA分子中应做
的事情。（Article p. 433）


钠熔化温度在压力诱导下下降的原因（Sodium under pressure）
Electronic and structural transitions in dense liquid sodium
研究人员最近发现，当施加高压时，锂和钠的晶体会发生一系列相变，包括一种
（对钠来说）另人吃惊的、但目前尚未得到解释的现象——钠熔化温度在压力诱
导下的下降。现在，Jean-Yves Raty等人识别出了这一异常熔化行为的原因：它
的出现是因为液态钠经历了一系列转变，与在固态中所见的转变相似，但所处压
力要低得多。有趣的是，这些转变中的一个是由电子状态密度中一个“假间隙”
的开放驱动的，这是这样一个效应首次在一种液态金属中被观测到。（Letter
p. 448）


关于“西太平洋暖池” 上大气对流所起作用的证据（The warm pool’s hot）
Millennial-scale trends in west Pacific warm pool hydrology since the
Last Glacial Maximum
 “西太平洋暖池”（赤道太平洋西部一个温暖水域）上的大气对流是热带以外
地区热量和水蒸气的一个主要来源，所以这一过程在过去的全球气候变化中可能
扮演一个重要角色。这个角色此前一直不能确定，因为缺少来自这一地区的年代
明确的高分辨率气候记录。现在，我们已经有了这一缺失的数据，即来自北婆罗
洲三个洞穴石笋的一个氧同位素记录，它反映了过去27,000年千年时间尺度上的
热带太平洋水文变化。该记录表明，热带太平洋水文周期对于北半球和南半球的
高纬度气候过程以及外部辐射力都是敏感的，而且它可能在突发气候变化事件中
曾经扮演一个重要角色。（Letter p. 452）


中国华东地区最早的农田水利设施（A first in the field?）
Fire and flood management of coastal swamp enabled first rice paddy
cultivation in east China
华东是早期的一个水稻栽培中心，但人们对该地区最早的农业系统却知之甚少。
来自华东已知最早新石器时代遗址（距今大约7,700年前）的新的生态证据表
明，新石器时代群落选择低地沼泽来栽培水稻。为了防止稍咸的水定期淹没稻
田，人们采用的办法可能是修建堤坝，这种堤坝既能防止发生大洪水将稻田淹
没，又能保留一些含有丰富养分的季节性洪水。这样就可以保证水稻高产所需的
稳定供水。这个地点的开发利用在距今大约7,550年前被海水淹没后就停止了。
这意味着水稻耕作要比以前所证明的古老得多，在从中石器时代的狩猎生活向新
石器时代定居农业经济转变（人类文化史上的一个关键性转变）开始就存在了。
（Letter p. 459）


葡萄基因组完成测序（Grapes go fourth）
The grapevine genome sequence suggests ancestral hexaploidization in
major angiosperm phyla
本期Nature发表了葡萄的基因组序列。这是已测序的第四种开花植物的基因组序
列、第二种木质植物的基因组序列和第一种果木的基因组序列。 该新序列的重
要意义在于它揭示了基因复制在开花植物演化中的作用。但为什么非遗传学家对
其感兴趣的原因主要是它的商业应用。这种葡萄的品种是Pinot Noir。（Letter
p. 463）


OR7D4受体基因变异对气味感觉的影响（Androstenone aroma）
Genetic variation in a human odorant receptor alters odour perception
不同人对特定气味的敏感性及他们对这些气味的主观体验都有很大差异。一项新
的研究首次表明，人体一个单一气味受体中所发生的遗传变异与人的感觉差异相
关。OR7D4是一种气味受体，在体外可被Androstenone选择性激发，后者是一种
睾丸酮代谢物，被一些人认为是一种催情药，称作“佛洛蒙”。编码OR7D4的基
因发生的变异会影响有这种变异的人是怎样想Androstenone的气味的——有些人
认为它很好闻，另一些人则认为它很讨厌，还有一些人会发现它没有气味，同时
也会影响人对这种气味的感觉又有多强烈。（Letter p. 468）


细胞的“转分化”和“脱分化”（Differentiation reversed）
Conversion of mature B cells into T cells by dedifferentiation to
uncommitted progenitors
成熟分化的细胞类型是怎样被控制的、通过充分分化的细胞类型能够实现什么程
度的发育弹性？这是发育生物学和干细胞研究中一个重要的、基础性的问题。这
个领域的一个中心问题，即细胞是通过直接“转分化”
（transdifferentiation）被直接重新编程为一种不同细胞类型的、还是在沿被
称为“脱分化”（dedifferentiation）的另一条路径前进之前采取了一个向后
的步骤而进入一种更不成熟的状态，由本期Nature上发表的一篇研究报告得到了
回答。Cobaleda等人演示了在成熟B-淋巴瘤细胞转化成功能性T-细胞过程中的
“脱分化”。Pax5（一个对于B-细胞分化和功能很重要的转录因子）的删除引起
成熟B-细胞脱分化成能够产生T-细胞的先祖细胞。Pax5已知在癌症中也扮演一个
角色，它的缺失已知能诱发由先祖细胞形成的淋巴瘤。（Letter p. 473; News
& Views）




----------------------
NEWS AND VIEWS
----------------------
Environmental science: Forests and floods pp409 - 410
One strategy for reducing catastrophic floods invokes protecting or
regenerating forests that lie upstream of a threatened region. Support
for this approach comes from a global-scale analysis of flood risk.
William F. Laurance
doi:10.1038/449409a
http://www.nature.com/nature/journal/v449/n7161/full/449409a.html

Immunology: Changed destiny pp410 - 411
For practical and ethical reasons, researchers are on the lookout for
ways to reprogramme one mature cell type into another. In one case,
this might be as easy as switching off a single gene.
Huafeng Xie and Stuart H. Orkin
doi:10.1038/449410a
http://www.nature.com/nature/journal/v449/n7161/full/449410a.html

Nuclear physics: A non-disappearing magic trick pp411 - 413
Well-established models of nuclei describe properties such as shells
and magic numbers. But how do these predictions stand up to scrutiny
for exotic, unstable nuclei? Pretty well, according to the latest
study.
Ragnar Bengtsson and Peter Moller
doi:10.1038/449411a
http://www.nature.com/nature/journal/v449/n7161/full/449411a.html

Evolutionary biology: Development with a bite pp413 - 415
Predictions drawn from experiments on the growth of molar teeth in
mice, and applied to a wide range of related species, provide a
remarkable connection between developmental and evolutionary biology.
P. David Polly
doi:10.1038/449413a
http://www.nature.com/nature/journal/v449/n7161/full/449413a.html

50 & 100 Years Ago p414
doi:10.1038/449414a
http://www.nature.com/nature/journal/v449/n7161/full/449414a.html

Quantum physics: Qubits ride the photon bus pp415 - 417
Quantum mechanics using whole electrical circuits might seem a
far-fetched idea. But make the circuits superconducting, and they can
be used to send and collect single photons, rather like atoms do ―
only better.
Antti O. Niskanen and Yasunobu Nakamura
doi:10.1038/449415a
http://www.nature.com/nature/journal/v449/n7161/full/449415a.html

Genomics: Vine work p417
Charles Wenz
doi:10.1038/449417a
http://www.nature.com/nature/journal/v449/n7161/full/449417a.html

----------------------
REVIEWS
----------------------
Taking dendritic cells into medicine pp419 - 426
Ralph M. Steinman and Jacques Banchereau
doi:10.1038/nature06175
Abstract:
http://www.nature.com/nature/journal/v449/n7161/abs/nature06175.html
Article:
http://www.nature.com/nature/journal/v449/n7161/full/nature06175.html

----------------------
ARTICLES
----------------------
Predicting evolutionary patterns of mammalian teeth from
development pp427 - 432
A test-bed system for examining how development guides evolutionary
change is the arrangement of molars in mice. The first molar is larger
than the one behind, which is in turn larger than the third, hindmost
molar. Experimental investigations have shown that molar development
follows an inhibitory cascade model, and the results are used to show
how this simple model governs the variation in molar size and number
in rodent evolution.
Kathryn D. Kavanagh, Alistair R. Evans and Jukka Jernvall
doi:10.1038/nature06153
Abstract:
http://www.nature.com/nature/journal/v449/n7161/abs/nature06153.html
Article:
http://www.nature.com/nature/journal/v449/n7161/full/nature06153.html

Enzymatic capture of an extrahelical thymine in the search for uracil
in DNA pp433 - 437
The enzyme uracil DNA glycosylase does not actively extrude just the
uracil base from the DNA helix to facilitate its removal; instead,
transient, passive opening of thymine: adenine and uracil: adenine
base pairs allows both thymine and uracil to become extrahelical, but
only uracil can subsequently fit in the active site.
Jared B. Parker et al.
doi:10.1038/nature06131
Abstract:
http://www.nature.com/nature/journal/v449/n7161/abs/nature06131.html
Article:
http://www.nature.com/nature/journal/v449/n7161/full/nature06131.html

----------------------
LETTERS
----------------------
Coherent quantum state storage and transfer between two phase qubits
via a resonant cavity pp438 - 442
One of two papers that demonstrate the communication of individual
quantum states between superconducting qubits via a quantum bus. This
quantum bus is a resonant cavity formed by a superconducting
transmission line of several millimetres. Quantum information,
initially defined in one qubit on one end, can be stored in this
quantum bus and at a later time retrieved by a second qubit at the
other end.
Mika A. Sillanpaa, Jae I. Park and Raymond W. Simmonds
doi:10.1038/nature06124
Abstract:
http://www.nature.com/nature/journal/v449/n7161/abs/nature06124.html
Article:
http://www.nature.com/nature/journal/v449/n7161/full/nature06124.html

Coupling superconducting qubits via a cavity bus pp443 - 447
One of two papers that demonstrate the communication of individual
quantum states between superconducting qubits via a quantum bus. This
quantum bus is a resonant cavity formed by a superconducting
transmission line of several millimetres. Quantum information,
initially defined in one qubit on one end, can be stored in this
quantum bus and at a later time retrieved by a second qubit at the
other end.
J. Majer et al.
doi:10.1038/nature06184
Abstract:
http://www.nature.com/nature/journal/v449/n7161/abs/nature06184.html
Article:
http://www.nature.com/nature/journal/v449/n7161/full/nature06184.html

Electronic and structural transitions in dense liquid sodium pp448
- 451
When high pressures are applied, crystals of lithium and sodium
undergo a sequence of phase transitions, including a striking
pressure-induced drop in the melting temperature. The cause of the
unusual melting behaviour has now been identified: it emerges because
liquid sodium undergoes a series of transitions similar to those seen
in the solid state, but at much lower pressures. One of these
transitions is driven by the opening of a 'pseudogap' in the
electronic density of states.
Jean-Yves Raty, Eric Schwegler and Stanimir A. Bonev
doi:10.1038/nature06123
Abstract:
http://www.nature.com/nature/journal/v449/n7161/abs/nature06123.html
Article:
http://www.nature.com/nature/journal/v449/n7161/full/nature06123.html

Millennial-scale trends in west Pacific warm pool hydrology since the
Last Glacial Maximum pp452 - 455
Oxygen isotope records from stalagmites in Northern Borneo reflect
changes in tropical Pacific hydrology on millennial timescales over
the past 27,000 years. The records indicate that the tropical Pacific
hydrological cycle is sensitive to high-latitude climate processes in
both hemispheres, as well as to external radiative forcing, and that
it may have played an important role in abrupt climate change events.
Judson W. Partin et al.
doi:10.1038/nature06164
Abstract:
http://www.nature.com/nature/journal/v449/n7161/abs/nature06164.html
Article:
http://www.nature.com/nature/journal/v449/n7161/full/nature06164.html

Metal saturation in the upper mantle pp456 - 458
High-pressure experiments are used to show that large parts of the
Earth's asthenosphere are metal-saturated, demonstrating that
oxidation is only a shallow phenomenon restricted to an upper veneer
only about 250 km depth.
Arno Rohrbach et al.
doi:10.1038/nature06183
Abstract:
http://www.nature.com/nature/journal/v449/n7161/abs/nature06183.html
Article:
http://www.nature.com/nature/journal/v449/n7161/full/nature06183.html

Fire and flood management of coastal swamp enabled first rice paddy
cultivation in east China pp459 - 462
Detailed evidence from the earliest known Neolithic site in eastern
China, around 7,700 years ago, demonstrates that Neolithic communities
selected lowland swamps for their rice cultivation. The results
establish that rice cultivation began in coastal wetlands of eastern
China, an ecosystem vulnerable to coastal change but of high fertility
and productivity, attractions maximised for about two centuries by
sustained high levels of cultural management of the environment.
Y. Zong et al.
doi:10.1038/nature06135
Abstract:
http://www.nature.com/nature/journal/v449/n7161/abs/nature06135.html
Article:
http://www.nature.com/nature/journal/v449/n7161/full/nature06135.html

The grapevine genome sequence suggests ancestral hexaploidization in
major angiosperm phyla pp463 - 467
A French and Italian consortium has produced sequence and analysis of
Vitis vinifera PN40024, a grapevine originally derived from Pinot
Noir. As you might expect, the grapevine has twice as many terpene
synthases as other sequenced plants; these enzymes contribute to
resins, essential oils and aromas.

doi:10.1038/nature06148
Abstract:
http://www.nature.com/nature/journal/v449/n7161/abs/nature06148.html
Article:
http://www.nature.com/nature/journal/v449/n7161/full/nature06148.html

Genetic variation in a human odorant receptor alters odour
perception pp468 - 472
In humans, there is considerable variation between individuals in
their sensitivity to certain smells and their subjective experience of
them. This paper identifies a potential genetic source of variability
in perception of odorous steroids. OR7D4, an odorant receptor, is
selectively activated in vitro by androstenone and variants of the
gene are associated with differences in psychophysical performance in
human subjects
Andreas Keller et al.
doi:10.1038/nature06162
Abstract:
http://www.nature.com/nature/journal/v449/n7161/abs/nature06162.html
Article:
http://www.nature.com/nature/journal/v449/n7161/full/nature06162.html

Conversion of mature B cells into T cells by dedifferentiation to
uncommitted progenitors pp473 - 477
Pax5 is a transcription factor important for B cell differentiation
and function. Deletion of Pax5 in mature B cells causes them to
de-differentiate to less differentiated progenitor cells that can give
rise to T cells, demonstrating an unanticipated degree of
developmental plasticity in this lineage.
Cesar Cobaleda, Wolfram Jochum and Meinrad Busslinger
doi:10.1038/nature06159
Abstract:
http://www.nature.com/nature/journal/v449/n7161/abs/nature06159.html
Article:
http://www.nature.com/nature/journal/v449/n7161/full/nature06159.html

IgH class switching and translocations use a robust non-classical
end-joining pathway pp478 - 482
Programmed DNA breaks are made and repaired at two points during the
development of antibody-producing B cells. While the breaks occurring
during V(D)J recombination utilize factors that promote non-homologous
end joining, this study finds that breaks that happen during class
switch recombination require only a subset of these factors,
suggesting that there are other as-yet-unrecognized proteins that
function in this process.
Catherine T. Yan et al.
doi:10.1038/nature06020
Abstract:
http://www.nature.com/nature/journal/v449/n7161/abs/nature06020.html
Article:
http://www.nature.com/nature/journal/v449/n7161/full/nature06020.html

Rag mutations reveal robust alternative end joining pp483 - 486
In the process of generating antibody diversity, DNA in the V(D)J
locus undergoes programmed double-strand breaks that are made by the
Rag1-Rag 2 complex. These breaks are repaired by the non-homologous
end-joining (NHEJ) pathway. Cells deficient in NHEJ factors show very
low levels of recombinants, so it was believed there might be another
repair pathway. But this paper shows that an alternative NHEJ pathway
exists, and that it functions at low levels even in wild-type cells.
Barbara Corneo et al.
doi:10.1038/nature06168
Abstract:
http://www.nature.com/nature/journal/v449/n7161/abs/nature06168.html
Article:
http://www.nature.com/nature/journal/v449/n7161/full/nature06168.html

Structural basis of Dscam isoform specificity pp487 - 491
Crystal structures of the amino-terminal four immunoglobulin domains
of two Dscam isoforms, coupled with biochemical analysis, reveals a
horseshoe-shaped configuration and an epitope that confers homophilic
dimerization specificity of Dscam receptors.
Rob Meijers et al.
doi:10.1038/nature06147
Abstract:
http://www.nature.com/nature/journal/v449/n7161/abs/nature06147.html
Article:
http://www.nature.com/nature/journal/v449/n7161/full/nature06147.html

Crystal structure of the heterotrimer core of Saccharomyces cerevisiae
AMPK homologue SNF1 pp492 - 495
AMP-activated protein kinase is a central regulator of energy
homeostasis in mammals, and the Saccharomyces cerevisiae homologue
SNF1 is essential for responses to nutrient starvation. This structure
reveals features such as the ligand-binding site in the γ-subunit,
the carbohydrate-binding domain in the β-subunit and a regulatory
sequence in the α-subunit.
Gabriele A. Amodeo, Michael J. Rudolph and Liang Tong
doi:10.1038/nature06127
Abstract:
http://www.nature.com/nature/journal/v449/n7161/abs/nature06127.html
Article:
http://www.nature.com/nature/journal/v449/n7161/full/nature06127.html

Structural basis for AMP binding to mammalian AMP-activated protein
kinase pp496 - 500
AMP-activated protein kinase (AMPK) is a central regulator of energy
homeostasis in mammals. This crystal structure of the trimeric
regulatory fragment of mammalian AMPK reveals the modes of AMP and ATP
binding.
Bing Xiao et al.
doi:10.1038/nature06161
Abstract:
http://www.nature.com/nature/journal/v449/n7161/abs/nature06161.html
Article:
http://www.nature.com/nature/journal/v449/n7161/full/nature06161.html

 
    
 


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