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2007年11月22日Nature中文摘要
封面故事:体细胞核转移方法成功用于灵长类动物
Producing primate embryonic stem cells by somatic cell nuclear
transfer
对成年细胞重新进行编码的方法是人们苦苦追寻的,因为通过这种方式可以生成
与患者的细胞在遗传上能够匹配的细胞。这样的胚胎干细胞也许可用于治疗,而
不会产生免疫排斥。重新编码的一种方法是体细胞核转移,即把一个成年细胞核
插进一个卵母细胞中,而这个卵母细胞已将自己的核去掉。这样可诱导形成一个
早期阶段的胚胎(胚泡),从它上面又可提取并培养出胚胎干细胞。以前,只有
对小鼠才有可能做到这一点。现在,Byrne等人已经成功将这种方法用于灵长类
动物。他们以灵长类成年成纤维细胞为起点,从来自14只猕猴的304个卵母细胞
培育出了两个胚胎干细胞系。这一成功说明,该方法也许适合生成来自患者的胚
胎干细胞。Nature杂志网站上还发表了与该论文及News & Views文章相伴的一篇
确证论文。本期封面所示为除核前的一个卵子。 该卵子被一个移液管所固定,
其右边是一个用来除核的尖尖的移液管,其端部指向该卵子的细胞核。
(Article p. 497, News & Views; www.nature.com/podcast)。
(doi:10.1038/nature 06456)


不知道害怕的小鼠(Tom and Jerry it’s not)
Innate versus learned odour processing in the mouse olfactory bulb
照片上的小鼠不知道害怕。更准确地说,它对于讨厌的气味不能产生先天性的行
为反应,而这种反应正常情况下可以保护小鼠不去吃腐烂的食物或避开某种捕食
者的气味。在这种小鼠中,其嗅觉上皮的一个区域(鼻腔内一个对气味敏感的上
皮组织)中的嗅觉神经元已经被白喉毒素基因的定向表达除掉了。虽然没有先天
的厌恶行为,但该小鼠却能探测和辨别讨厌的气味,并且可以条件性地做出厌恶
反应。这些结果表明,同免疫系统一样,小鼠的嗅觉系统也具有“硬件连接
的”、通过遗传程序编码的神经回路,它们与后天获得的、与先天系统联系在一
起的适应性回路是并行的。
(Article p. 503)


大气成分主要为碳的白矮星(CARBON COPIES)
White dwarf stars with carbon atmospheres
白矮星是一些较小恒星的演化终点。它们一般来说有两种形式:要么有富含氢的
大气,要么有富含氦的大气。因此,几颗大气主要由碳组成的白矮星的发现是出
乎意料的。虽然非常罕见,但这一新的恒星类型却似乎代表着恒星演化的另一条
路径。
(Letter p. 522)


一种高温铜氧化物超导体的表面结构(Pocket change)
Electron pockets in the Fermi surface of hole-doped high-Tc
superconductors
最近的一篇论文(Nature 447, 565-568; 2007)详细阐述了一种由空穴掺杂的
高温铜氧化物超导体在其正常金属状态下的电子结构。在未充分掺杂的材料(由
小袋组成)中观测到的费米表面被发现与在过度掺杂的材料中观测到的费米表面
形成鲜明对比,并且与传统金属的费米表面也很不一样。现在,David LeBoeuf
等人通过对“Hall效应”进行测量发现,费米表面中的这些结构是“电子小袋”
(electron pockets),而不是像最初所怀疑的是“空穴小袋”(hole
pockets)。这种小袋的形成有可能是由一种神秘的、能够打破对称的相所产生
的一个结果,与在一些由电子掺杂的氧化铜中所看到的相似。这种复杂的相似乎
是氧化铜的一个普遍性质,因此它预计也许在决定高温超导体性质中扮演一个中
心角色。
(Letter p. 533; News & Views)


北美和北欧冰川地区地表水变棕的原因(Brown waters)
Dissolved organic carbon trends resulting from changes in atmospheric
deposition chemistry
关于北美和北欧很多偏远冰川化地区地表水随所溶解有机碳浓度增加而变得越来
越呈现棕色的报道非常多。人们提出了几个假设来解释这一效应,其中包括最近
的气候变化,但这个问题仍然存在争议。现在,一项新的研究工作,将对来自超
过500个偏远湖泊和溪流的时间序列数据所进行的分析与一个简单模型结合了起
来,发现所溶解的有机碳浓度实际上是与大气沉降物中硫酸盐和海盐含量的下降
密切相关。因此,溶解的有机碳浓度也许正在向19世纪酸雨第一次出现之前典型
的浓度水平回归。
(Letter p. 537)


海洋浮游植物对二氧化碳的吸收(Ocean carbon dioxide)
Enhanced biological carbon consumption in a high CO2 ocean
工业化以来由化石燃料所产生的二氧化碳有近一半已被海洋吸收,造成可以测量
得出的酸化和碳酸盐饱和。最近一系列研究报告提出,如果由人类活动造成的二
氧化碳生产不加限制地继续下去,那么未来将会发生严重的海水酸化。 以前的
研究工作主要针对酸化对各海洋物种的影响。现在,在挪威的Raune Fjord所进
行的一项实验研究中,研究人员利用环境尺度的中型受控生态系统对二氧化碳吸
收在一个自然群落生态系统中的效应进行了估计。结果表明, 海洋浮游植物的
二氧化碳消耗因该气体浓度增加所产生的空间压力而明显增加,而营养摄取却没
有变化。如果这个结果能够应用于整个海洋,那么这一生物反馈效应也许就是大
气二氧化碳浓度的一个重要限制因素。
(Letter p. 545; News & Views)


裸子植物化石研究(Seeds of time)
Phase-contrast X-ray microtomography links Cretaceous seeds with
Gnetales and Bennettitales
关于开花植物出现时间的研究工作因很多保存完好的花粉化石的发现而在过去25
年里发生了革命性变化。但裸子植物(针叶树)化石所受到的关注却不是那么
多。Friis等人利用一种最近开发出的同步辐射X-射线断层扫描技术改变了这种
状况。它们获得的图像以高分辨率显示了内部结构。一些白垩纪裸子植物的种子
结构表明,买麻藤目(Gnetales)(一个模糊的、在进化上难以确定位置的裸子
植物类群,有三个现存的属)和Bennetitales (一种像苏铁的已经绝灭的重要
植物类群)之间存在着演化联系。
(Letter p. 549)


抗抑郁剂“米安色林”能延长寿命(A long life but a happy one?)
An antidepressant that extends lifespan in adult Caenorhabditis
elegans
对线虫Caenorhabditis elegans体内能够延长寿命的化学成分所进行的一项大规
模筛选得出一个让人吃惊的结果:“米安色林”——一种用作人类抗抑郁症药物
的化合物——能够将线虫3个星期的寿命延长近三分之一。在人体中,这种药物
通过神经传递物质5-羟色胺阻断神经信号作用; 而其能够延长线虫寿命的效应
似乎也涉及5-羟色胺和章鱼胺(octopamine)受体的阻断。其他相关的抗抑郁剂
也有一个类似的效应,用不同突变体所做的试验表明,该药物延长寿命的效应所
涉及的机制与通过节制饮食来延长寿命的机制相似。一种可能性是,“米安色
林”诱发了一种感觉到的、而非真正的饥饿状态。有趣的是,刺激胃口是“米安
色林”在人体中的一个副作用。所以存在这样一个可能性:胃口好坏和寿命长短
在线虫身上和在人类身上也许都是相联系的。
(Letter p. 553; www.nature.com/podcast])


婴儿也能辨别是非(Start them young)
Social evaluation by preverbal infants
成功社会互动的关键是具有准确评估对方(不管是朋友还是敌人)意图的能力。
对人类来说,这种能力在生命的非常早的时期就存在了。对6个月和10个月大的
婴儿所做的一项新的研究表明,人类开始进行社会评估的时间甚至比我们所认为
的还要早,即在他们学会使用语言之前就开始了。参加该研究的婴儿能够根据行
为者的社会行为来对他们进行评估——他们会被一个帮助某一不相关的第三方去
实现他或她的目标的人所吸引,而会避开一个妨碍某一第三方实现目标的人。这
些发现支持这样一个观点:成年人的社会评估行为的某些前身特征甚至在婴儿身
上也是存在的。这种技能可能是一种生物学上的适应性,它也可能是后天道德思
想和行为的基础。
(Letter p. 557)


白蚁为什么能吃木料?(How termites eat wood)
Metagenomic and functional analysis of hindgut microbiota of a
wood-feeding higher termite
吃木料的高等白蚁是一个极为成功的动物类群,在帮助环境中的碳周转方面发挥
一个重要功能。进行那些使得白蚁的生活方式成为可能的关键反应的并不是白蚁
本身,而是在它们的后肠中所发现的能够降解木质纤维素的共生细菌。对来自哥
斯达黎加一个雨林的超过150只树生白蚁的肠道细菌所做的一项环境基因组分
析,显示了一系列不同的细菌纤维素酶和木质糖水解酶基因以及在其他共生功能
中重要的基因。该数据集包括大约1000种细菌木质纤维素水解酶同源物质,它们
当中有些是在活白蚁身上原位表达的。 这项工作表明,白蚁是有可能在将木质
材料转化成生物燃料的过程中使用的细菌酶的一个丰富来源。
(Letter p. 560)


植物防止晒伤的机制(Plants feel the heat)
Identification of a mechanism of photoprotective energy dissipation in
higher plants
植物要生长的话就需要阳光,但如果阳光太强烈,它们就会被晒伤。为了保护自
己不被晒伤, 植物叶绿体中用于利用光线的“天线”在阳光太强时会迅速地、
可逆地切换到一种光保护关闭状态。然后,其所吸收的有潜在危害的能量就会以
热量形式耗散掉。对于这种能量耗散过程的机制,研究人员在完好的叶绿体膜中
和整片叶子中已经用振动莱曼光谱进行了研究。结果表明,绿色植物主要光利用
复合物LHCII在不同环境条件下能在不同构型状态之间进行切换,以调控能量
流,从而控制在为进行光合作用而有效利用光能和在以热量形式耗散光能之间的
平衡。
(Letter p. 575)


----------------------
NEWS AND VIEWS
----------------------
Stem cells: Primates join the club pp485 - 486
Researchers have achieved the testing goal of generating embryonic
stem cells from the cells of an adult primate. The procedure used
could provide insights into a variety of diseases, if it can be
applied in humans.
Ian Wilmut and Jane Taylor
doi:10.1038/450485a
http://www.nature.com/nature/journal/v450/n7169/full/450485a.html

Materials science: Purity rolled up in a tube pp486 - 487
Before carbon nanotubes can fulfil their potential in device
applications, better ways must be found to produce pure samples of
them. A promising approach involves wrapping them up in a shell of
polymer.
Fotios Papadimitrakopoulos and Sang-Yong Ju
doi:10.1038/450486a
http://www.nature.com/nature/journal/v450/n7169/full/450486a.html

Microbiology: Woodworker's digest pp487 - 488
Termites digest wood with the help of their intestinal microorganisms.
The first metagenomic analysis of the inhabitants of a termite gut
provides insight into this feat of biomass-to-energy conversion.
Andreas Brune
doi:10.1038/450487a
http://www.nature.com/nature/journal/v450/n7169/full/450487a.html

Astronomy: Sloan at five pp488 - 489
The Sloan Digital Sky Survey represents the most ambitious attempt yet
to map out a slice of the sky. In the first five years of its
existence, it has revealed cosmic structures on every conceivable
scale.
Robert C. Kennicutt Jr
doi:10.1038/450488a
http://www.nature.com/nature/journal/v450/n7169/full/450488a.html

Earth science: Sediment en route to oblivion pp490 - 491
Sudden collapses of the sea floor can generate oceanic sediment flows
that dwarf the global annual sediment input from rivers. Such flows
can travel great distances, and undergo transformation along the way.
Philip A. Allen
doi:10.1038/450490a
http://www.nature.com/nature/journal/v450/n7169/full/450490a.html

Carbon cycle: Marine manipulations pp491 - 492
The effect of increasing levels of atmospheric carbon dioxide on
carbon uptake in and export from the upper ocean is one of the big
questions in environmental science. But it can be tackled
experimentally.
Kevin R. Arrigo
doi:10.1038/450491a
http://www.nature.com/nature/journal/v450/n7169/full/450491a.html

High-temperature superconductivity: Schizophrenic electrons pp492
- 493
The split personality of the conduction electrons in one
high-temperature superconductor might indicate that periodic
modulations of their spin and charge density are a general feature of
these mystifying materials.
Christian Pfleiderer and Rudi Hackl
doi:10.1038/450492a
http://www.nature.com/nature/journal/v450/n7169/full/450492a.html

----------------------
FEATURE
----------------------
Grand challenges in chronic non-communicable diseases pp494 - 496
The top 20 policy and research priorities for conditions such as
diabetes, stroke and heart disease.
Abdallah S. Daar et al.
doi:10.1038/450494a
http://www.nature.com/nature/journal/v450/n7169/full/450494a.html

----------------------
ARTICLES
----------------------
Producing primate embryonic stem cells by somatic cell nuclear
transfer p497
The reprogramming of rhesus macaque adult fibroblasts into embryonic
stem cells using somatic cell nuclear transfer is demonstrated. Until
now, creating embryonic stem cells in this way has only been
successful in mice. This success with primates suggests that this
approach could work for generating patient-derived embryonic stem
cells, which could be used to treat a variety of diseases without
immune rejection.
J. A. Byrne et al.
doi:10.1038/nature06357
http://www.nature.com/nature/journal/v450/n7169/abs/nature06357.html
http://www.nature.com/nature/journal/v450/n7169/full/nature06357.html

Innate versus learned odour processing in the mouse olfactory bulb
p503
Michael L. Oldham et al.
doi:10.1038/nature06281
http://www.nature.com/nature/journal/v450/n7169/abs/nature06281.html
http://www.nature.com/nature/journal/v450/n7169/full/nature06281.html

Human CtIP promotes DNA end resection p509
Alessandro A. Sartori et al.
doi:10.1038/nature06337
http://www.nature.com/nature/journal/v450/n7169/abs/nature06337.html
http://www.nature.com/nature/journal/v450/n7169/full/nature06337.html

Crystal structure of a catalytic intermediate of the maltose
transporter pp515 - 521
The crystal structure of the maltose transporter, in complex with its
periplasmic maltose-binding protein, at 2.8 ? resolution is presented.
Because both ATP and maltose are bound and a mutation that prevents
ATP hydrolysis has been introduced, the complex has been captured in
an intermediate state and a mechanism for maltose transport proposed.
Michael L. Oldham et al.
doi:10.1038/nature06264
Abstract:
http://www.nature.com/nature/journal/v450/n7169/abs/nature06264.html
Article:
http://www.nature.com/nature/journal/v450/n7169/full/nature06264.html

----------------------
LETTERS
----------------------
White dwarf stars with carbon atmospheres pp522 - 524
The discovery of several white dwarfs with atmospheres primarily
composed of carbon, with little or no trace of hydrogen or helium is
reported. These stars do not fit satisfactorily in any of the
currently known theories of post-asymptotic giant branch evolution.
P. Dufour, J. Liebert, G. Fontaine and N. Behara
doi:10.1038/nature06318
Abstract:
http://www.nature.com/nature/journal/v450/n7169/abs/nature06318.html
Article:
http://www.nature.com/nature/journal/v450/n7169/full/nature06318.html

Coupled 142Nd-143Nd evidence for a protracted magma ocean in
Mars pp525 - 528
V. Debaille, A. D. Brandon, Q. Z. Yin and B. Jacobsen
doi:10.1038/nature06317
Abstract:
http://www.nature.com/nature/journal/v450/n7169/abs/nature06317.html
Article:
http://www.nature.com/nature/journal/v450/n7169/full/nature06317.html

Coherent zero-state and π-state in an exciton-polariton condensate
array pp529 - 532
A microcavity structure to which a periodic potential is applied has
been designed, which effectively creates an array of weakly-coupled
condensates. This allows the observation of fundamental dynamic
behaviour, namely the build-up of certain superfluid-like states,
which has been predicted for arrays of atomic Bosea-Einstein
condensates, but not yet observed.
C. W. Lai et al.
doi:10.1038/nature06334
Abstract:
http://www.nature.com/nature/journal/v450/n7169/abs/nature06334.html
Article:
http://www.nature.com/nature/journal/v450/n7169/full/nature06334.html

Electron pockets in the Fermi surface of hole-doped high-Tc
superconductors pp533 - 536
The observation of a negative Hall resistance in the
magnetic-field-induced normal state of underdoped 'YBCO'materials,
which reveals that these pockets are electron-like rather than
hole-like. It is proposed that these electron pockets most probably
arise from a reconstruction of the Fermi surface caused by the onset
of a density-wave phase, as is thought to occur in the electron-doped
copper oxides near the onset of antiferromagnetic order.
David LeBoeuf et al.
doi:10.1038/nature06332
Abstract:
http://www.nature.com/nature/journal/v450/n7169/abs/nature06332.html
Article:
http://www.nature.com/nature/journal/v450/n7169/full/nature06332.html

Dissolved organic carbon trends resulting from changes in atmospheric
deposition chemistry pp537 - 540
The use of time series data from 522 remote lakes and streams in North
America and northern Europe and a simple model shows that dissolved
organic carbon concentrations between 1990-2004 have increased in
proportion to the rates at which atmospherically deposited
anthropogenic sulphur and sea salt have declined. It is suggested that
acid deposition to these ecosystems has been partially buffered by
changes in organic acidity and that the rise in dissolved organic
carbon is integral to recovery from acidification.
Donald T. Monteith et al.
doi:10.1038/nature06316
Abstract:
http://www.nature.com/nature/journal/v450/n7169/abs/nature06316.html
Article:
http://www.nature.com/nature/journal/v450/n7169/full/nature06316.html

Onset of submarine debris flow deposition far from original giant
landslide pp541 - 544
P. J. Talling et al.
doi:10.1038/nature06313
Abstract:
http://www.nature.com/nature/journal/v450/n7169/abs/nature06313.html
Article:
http://www.nature.com/nature/journal/v450/n7169/full/nature06313.html

Enhanced biological carbon consumption in a high CO2 ocean p545
U. Riebesell, K. G. Schulz, R. G. J. Bellerby, M. Botros, P. Fritsche,
M. Meyerh?fer, C. Neill, G. Nondal, A. Oschlies, J. Wohlers & E.
Z?llner
doi:10.1038/nature06267
http://www.nature.com/nature/journal/v450/n7169/abs/nature06267.html
http://www.nature.com/nature/journal/v450/n7169/full/nature06267.html

Phase-contrast X-ray microtomography links Cretaceous seeds with
Gnetales and Bennettitales pp549 - 552
A relatively new imaging technique is used to reveal that some
Cretaceous gymnosperm seeds have evolutionary links with Gnetales (an
evolutionarily hard-to-place gymnosperm group with three living
genera) and the Bennetitales (an extinct group of cycad-like plants).
The link between Gnetales and Bennetitales may have important
consequences for our understanding of the evolution of seed plants,
including flowering plants.
Else Marie Friis et al.
doi:10.1038/nature06278
Abstract:
http://www.nature.com/nature/journal/v450/n7169/abs/nature06278.html
Article:
http://www.nature.com/nature/journal/v450/n7169/full/nature06278.html

An antidepressant that extends lifespan in adult Caenorhabditis
elegans pp553 - 556
A drug used as an antidepressant in humans increases Caenorhabditis
elegans lifespan. In humans, this drug blocks neural signalling by the
neurotransmitter serotonin. In C. elegans, it seems to act as an
antagonist for the serotonin receptor and for the receptor of the
neurotransmitter octopamine. The drug's effect on lifespan seems to
involve mechanisms similar to those that underlie lifespan extension
by dietary restriction.
Michael Petrascheck, Xiaolan Ye and Linda B. Buck
doi:10.1038/nature05991
Abstract:
http://www.nature.com/nature/journal/v450/n7169/abs/nature05991.html
Article:
http://www.nature.com/nature/journal/v450/n7169/full/nature05991.html

Social evaluation by preverbal infants pp557 - 559
The key to successful social interactions is the ability to accurately
assess others' intentions, be they friend or foe. In humans, this
ability is present very early on in life, as is shown here when
preverbal infants evaluate individuals based on their actions towards
others, preferring helpers to neutral or hindering individuals.
J. Kiley Hamlin, Karen Wynn and Paul Bloom
doi:10.1038/nature06288
Abstract:
http://www.nature.com/nature/journal/v450/n7169/abs/nature06288.html
Article:
http://www.nature.com/nature/journal/v450/n7169/full/nature06288.html

Metagenomic and functional analysis of hindgut microbiota of a
wood-feeding higher termite pp560 - 565
Wood-feeding 'higher' termites rely on their hindgut symbionts for the
intitial steps in cellulose degradation. Metagenomic analysis of this
microbial community reveals a diverse range of bacterial cellulase and
hydrolase genes, as well as genes important in other metabolic
functions, such as H2 metabolism, CO2-reductive acetogenesis and N2
fixation.
Falk Warnecke et al.
doi:10.1038/nature06269
Abstract:
http://www.nature.com/nature/journal/v450/n7169/abs/nature06269.html
Article:
http://www.nature.com/nature/journal/v450/n7169/full/nature06269.html

The inhibitory cytokine IL-35 contributes to regulatory T-cell
function pp566 - 569
Regulatory T cells suppress immune function by direct cell to cell
contact and secretion of the cytokines IL-10 and TGF-I2. In this
paper, a novel member of the IL-12 cytokine family that contributes to
Treg function is identified.
Lauren W. Collison et al.
doi:10.1038/nature06306
Abstract:
http://www.nature.com/nature/journal/v450/n7169/abs/nature06306.html
Article:
http://www.nature.com/nature/journal/v450/n7169/full/nature06306.html

A SNARE-adaptor interaction is a new mode of cargo recognition in
clathrin-coated vesicles pp570 - 574
The crystal structure of a SNARE protein bound to a clathrin adaptor
is reported, which reveals that there is highly specific interactions
between two folded domains as opposed to the linear peptide motif or
folded domains that have been described for other families of cargo
proteins. This is the first example of a SNARE association with a
clathrin adaptor and describes a novel mechanism by which cargo can be
recruited into clathrin coated vesicles.
Sharon E. Miller et al.
doi:10.1038/nature06353
Abstract:
http://www.nature.com/nature/journal/v450/n7169/abs/nature06353.html
Article:
http://www.nature.com/nature/journal/v450/n7169/full/nature06353.html

Identification of a mechanism of photoprotective energy dissipation in
higher plants pp575 - 578
LHCII, the main light-harvesting complex in photosynthesis, has an
inbuilt capability to undergo transformation into a dissipative state
by conformational change, but it was not known if such events occur in
vivo or how energy is dissipated in this state. The transition into
the dissipative state is associated with a twist in the configuration
of the LHCII-bound carotenoid neoxanthin identified using resonance
Raman spectroscopy. Applying this technique to study isolated
chloroplasts and whole leaves, this paper shows that the same change
in neoxanthin configuration occurs in vivo, to an extent consistent
with the magnitude of energy dissipation.
Alexander V. Ruban et al.
doi:10.1038/nature06262
Abstract:
http://www.nature.com/nature/journal/v450/n7169/abs/nature06262.html
Article:
http://www.nature.com/nature/journal/v450/n7169/full/nature06262.html
 
    
 


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