| 2005年07月21日 Nature中文摘要 | 点击： 作者： 来源： 时间： 2006-11-11 本站论坛
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|  | Volume 436 Number 7049 pp303-440
封面故事：脖子的演化
早期脊椎动物的脖子是不能活动的骨质桥，其两侧为鳍。这一简单结构在早期有颚鱼类中是怎样变成连接头部和肩部的可活动肌肉系统的，是按照胚胎发育来解释演化的“演化－发育学”中最难解释的问题之一。现在，一种新颖的命运绘图方法被用在转基因小鼠中，来在单细胞水平上追踪肩带区域的起源。对神经冠（封面上显示为绿色）和中胚层（封面上显示为红色）干细胞的起源所做的追踪显示出“无形的”边界，它们不是与骨骼结构一致，而是与肌肉-骨骼连接架的结构一致。这些连接架的模式在一种名为Eastmanosteus、与最基本有颚脊椎动物有关的化石鱼（封面上靠下的图片，“古脊椎动物学会”2003年版权所有，其重印和发布得到该学会的许可）和今天的哺乳动物（封面上靠上的图片）之间保存了4亿年。
北半球冰川化始于3400万年前
在距今5500万和3400万年前，地球从温暖的“温室”海洋气候体系变成我们今天的“冰室”气候体系。麻烦的是，关于这一关键时期的少量海洋学数据集分辨率都很低。现在，Tripati等人报告了他们对沉积物和有孔虫目动物地球化学性质的测定结果，该结果成为这一时期的第一个连续的高分辨率记录。所获得的数据表明，北半球冰川化开始于3400万年前，而不是像以前所认为的开始于距今1000万年和800万年前。
二型糖尿病的新靶点
脂肪组织中的胰岛素作用受影响是二型糖尿病的一个主要病因，现在一个以前未知的、也许能够促使这一过程发生的机制已被发现。以前，曾有报道说，糖尿病患者血清中维生素A的一种结合蛋白RBP4的含量增加，但没有怀疑到二者之间有因果关系。“全面基因表达分析”方法被用来识别脂肪组织中GLUT4葡萄糖转移因子功能受损（肥胖症和糖尿病的特征）的小鼠体内其表达发生改变的基因，结果显示RBP4含量增加。另外，增加正常小鼠血清中RBP4含量会引起胰岛素抗性，而用增强胰岛素敏感性的药物降低该蛋白在肥胖小鼠血清中的含量会减轻胰岛素抗性，说明降低RBP4也许是治疗二型糖尿病的一种可行方案。
陨石坑之间的大吃小现象
碰撞成坑作用是行星和小行星上的一个基本过程。研究人员已在地球上和通过宇宙飞船对陨石坑形成的很多方面进行了研究，但一个一直难以确认的现象是大型碰撞的地震效应。由NEAR-Shoemaker 宇宙飞船2000－2001年间环绕小行星Eros、对该小行星整个天体所做的详细测绘，显示出该天体表面小陨石坑受到破坏的明显格局。例如，一个较大的陨石坑的形成，抹去了该小行星近40%表面上的大多数较小的陨石坑。这一发现将使科学家能够对小行星和卫星的内部和表面特征进行推断。
欧洲大陆的强度
欧洲作为一个政治实体其力量正处在关键时候，因为欧盟需要应对最近一些成员国通过全民公决否决欧盟新宪法的问题。与此同时，地质学家中就欧洲人脚下土地的力量（强度）有多大也有一个争论。在大陆内，被称为“克拉通”（即稳定地块）的古老区域所遭受的变形要比其余的年轻区域小的多。地质学家所争论的是古老“克拉通”的相对强度问题，因为不同方法对Te值（即有效弹性厚度）有非常不同的估计结果。Perez-Gussinyé 和Watts确定了欧洲大陆各个不同点上的Te值。当厚度大约为60公里时，“克拉通”的刚性要比年轻大陆区域的刚性大的多，这说明当不同地块形成时，地幔中的主导条件是不同的。
强化在物种形成中的作用得到肯定
物种形成是演化生物学中最重要、人们了解最差的领域之一。该领域一个有争议的问题是强化，在此过程中，当新物种仍然能够杂交、但适应性降低时，自然选择是鼓励杂交的。最近的研究工作对自然种群中几个经典的强化例子提出了质疑，使曾经是达尔文理论构成部分的“强化说”不再正统，但一项新的研究又恢复了这一学说的正统地位。对一组名为Agrodiaetus、具有可变染色体数量的异常蝴蝶的演化史所做的分析表明，当密切相关的物种一起出现时，它们翅膀的颜色几乎总是不同。这是配偶选择中的一个关键特点，颜色的分异主要发生在年轻的和密切相关的物种之间，说明强化作为产生多样性的一个机制是有道理的。
深层沉积物和岩石中的细菌
最近科学家们在深层沉积物和岩石中发现，细菌似乎能够在几乎没有任何能量供给的情况下存活数百万年。这一发现具有深远意义。例如，它会影响到关于生命起源、其他行星上地表下是否存在生命、以及化石燃料的形成等等方面的理论。所以并不奇怪的是，关于上面所提到的发现存在相当大的争议。现在，一项新的调查显示，深层海洋沉积物中的细菌不仅是活跃的，而且它们在地表之下还受到在地质时间尺度上发生的化学和地质变化的刺激。
果蝇的“变性手术”
在求偶过程中，雄性果蝇会根据特定的感官提示表现出一系列先天性的有固有套路的行为。现在，主管这一行为的神经细胞群已经被识别出来。使这些神经细胞失去活性，足以使雄性果蝇对交配失去兴趣，而改变雌性果蝇的大脑、使其产生这些细胞所产生的同样蛋白，会使雌性果蝇表现出雄性果蝇特有的求偶行为。这些神经细胞产生一组被称为FruM的蛋白，由“无果基因”（fru）编码，后者以前曾被发现与雄性果蝇的求偶有关。使产生FruM的神经细胞失去活性，会抑制求偶行为，但不会改变果蝇行为的其他方面。操纵雌性果蝇的神经细胞使其产生FruM，足以使它们把其他雌性果蝇当成潜在交配对象。
Nipah病毒赖以感染人体细胞的一个关键受体
1999年首次识别出的Nipah病毒能使人患致命的脑炎。特别是孟加拉国，该病毒在这里曾发生过一系列流行事件。这种病毒的天然寄主被认为是食果蝙蝠，但它在猪和其他动物身上也有。该病毒对养猪业可能构成严重威胁，最近还发现了它在人与人之间传播的证据。现在该病毒赖以感染人体细胞的一个关键受体已被识别出来，由此我们可能会找到用药物或疫苗对付该病毒感染的方法来。该病毒的附着蛋白结合在ephrinB2受体上，该受体对于正常的血管发育过程至关重要，但在被Nipah病毒感染的组织中发现它的数量很大。EphB4酶能阻止该病毒进入细胞中。
本期目录：
Volume 436 Number 7049 pp303-440
Editorials
All together now p303
The decision to site the fusion experiment ITER in France left relatively little bad blood between the international partners, who must now rally behind the project.
doi: 10.1038/436303a
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Socialism in one country p303
Cuba's scientific community has made substantial progress in addressing social problems.
doi: 10.1038/436303b
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Agency under siege p304
Conflicts-of-interest at the US National Institutes of Health justify the agency's ethics crackdown.
doi: 10.1038/436304a
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Top of pageResearch Highlights
Research highlights p306
doi: 10.1038/436306a
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Top of pageNews
Psychologists warn of more suicide attacks in the wake of London bombs p308
Terror threat to the West 'will remain high for years to come', says analyst.
Jim Giles and Michael Hopkin
doi: 10.1038/436308a
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Altered embryos offered as solution to stem-cell rift p309
Senators seek way out of voting dilemma.
Erika Check
doi: 10.1038/436309a
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Bird flu: crossing borders p310
Despite recent reports from governments that bird flu is under control, it continues to spread through Asia's poultry and claim lives — there are even signs of human-to-human transmission. Declan Butler tracks the disease's inexorable spread.
doi: 10.1038/436310a
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Arsenic-free water still a pipedream p313
Decontamination plants fail to free millions from poisoned supply.
Philip Ball
doi: 10.1038/436313a
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Malaysia plans 'red book' in its attempts to go green p313
Biodiversity catalogue marks shift in attitude.
David Cyranoski
doi: 10.1038/436313b
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Asia squeezes Europe's lead in science p314
Global share of scientific output rises in the East.
Andreas von Bubnoff
doi: 10.1038/436314a
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Sidelines p315
doi: 10.1038/435315b
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Animal-rights group sues over 'disturbing' work on sea lions p315
Conservation effort criticized for branding pups.
Rex Dalton
doi: 10.1038/436315a
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News in brief p316
doi: 10.1038/436316a
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Top of pageNews Features
Fusion energy: Just around the corner p318
For 50 years, physicists have been promising that power from nuclear fusion is imminent. Now they are poised to build an experiment that could vindicate their views. But will the machine work? Geoff Brumfiel investigates.
doi: 10.1038/436318a
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Cuban science: ?Vive la revolución? p322
Cuba's socialist science policies are producing top-notch research from scant economic resources. But, as Jim Giles reports, they have harsh consequences for scientists who do not fit in with government priorities.
doi: 10.1038/436322a
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Top of pageBusiness
Pumping up the volume p326
The business of writing popular science books is hard to break into — and even harder to make money out of. Tony Reichhardt reports.
doi: 10.1038/436326a
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In brief p327
doi: 10.1038/436327a
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Market watch p327
Quirin Schiermeier
doi: 10.1038/436327b
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Top of pageCorrespondence
Unlike climate science, GM is full of uncertainties p328
Douglas Parr
doi: 10.1038/436328a
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Leave GM analysis to the relevant scientists p328
Denis Couvet
doi: 10.1038/436328b
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Compensation for climate change must meet needs p328
W. Neil Adger and Jon Barnett
doi: 10.1038/436328c
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There's more to a colourful life than simply sex p328
Paul Kenton
doi: 10.1038/436328d
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Top of pageBooks and Arts
Letters from a hero p329
What made Richard Feynman so much more than a Nobel prizewinning physicist?
Peter Galison reviews Perfectly Reasonable Deviations from the Beaten Track: The Letters of Richard P. Feynman
doi: 10.1038/436329a
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Darwin's first love p330
Martin Rudwick reviews Charles Darwin, Geologist by Sandra Herbert
doi: 10.1038/436330a
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Documentary: In the right place at the right time p331
Henry Gee
doi: 10.1038/436331a
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Science in culture: A trick of the tiles p332
Penrose tiling is realized on a huge scale in Perth to give a perceptual feast for the eyes.
Martin Kemp
doi: 10.1038/436332a
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Top of pageNews and Views
Palaeoclimate: Foreshadowing the glacial era p333
Under what circumstances do glaciations persist or occur only transiently? Indications that short-lived 'icehouse' conditions occurred during the otherwise warm Eocene provide further cause for debate on the question.
Lee R. Kump
doi: 10.1038/436333a
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Behavioural genetics: Sex in fruitflies is fruitless p334
The courtship rituals of fruitflies are disrupted by mutations in the fruitless gene. A close look at the gene's products — some of which are sex-specific — hints at the neural basis of the flies' behaviour.
Charalambos P. Kyriacou
doi: 10.1038/436334a
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Asteroids: Shaken on impact p335
A single recent impact may have modified the craters on the asteroid Eros into the pattern we see today. This finding has implications for how we view the structure of asteroids — and for addressing any hazards they present.
Erik Asphaug
doi: 10.1038/436335a
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50 and 100 years ago p336
doi: 10.1038/436336a
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Metabolism: A is for adipokine p337
Adipokines are hormones that signal changes in fatty-tissue mass and energy status so as to control fuel usage. A fat-derived adipokine that binds to vitamin A provides a new link between obesity and insulin resistance.
Deborah M. Muoio and Christopher B. Newgard
doi: 10.1038/436337a
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Parasitology: Triple genome triumph p337
Declan Butler
doi: 10.1038/436337b
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Top of pageBrief Communications
Radiocarbon dating: Jewish inspiration of Christian catacombs p339
A Jewish cemetery in ancient Rome harbours a secret that bears on the history of early Christianity.
Leonard V. Rutgers, Klaas van der Borg, Arie F. M. de Jong and Imogen Poole
doi: 10.1038/436339a
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Top of pageBrief Communications Arising
Palaeoclimatology: Formation of Precambrian sediment ripples pE1
Douglas J. Jerolmack and David Mohrig
doi: 10.1038/nature04025
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Palaeoclimatology: Formation of Precambrian sediment ripples (reply) pE1
Philip Allen and Paul Hoffman
doi: 10.1038/nature04026
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Top of pageArticles
Eocene bipolar glaciation associated with global carbon cycle changes p341
Aradhna Tripati, Jan Backman, Henry Elderfield and Patrizia Ferretti
doi: 10.1038/nature03874
Abstract | Full Text | PDF (372K) | Supplementary information
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Neural crest origins of the neck and shoulder p347
Toshiyuki Matsuoka, Per E. Ahlberg, Nicoletta Kessaris, Palma Iannarelli, Ulla Dennehy, William D. Richardson, Andrew P. McMahon and Georgy Koentges
doi: 10.1038/nature03837
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Serum retinol binding protein 4 contributes to insulin resistance in obesity and type 2 diabetes p356
Qin Yang, Timothy E. Graham, Nimesh Mody, Frederic Preitner, Odile D. Peroni, Janice M. Zabolotny, Ko Kotani, Loredana Quadro and Barbara B. Kahn
doi: 10.1038/nature03711
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Top of pageLetters
Extreme collisions between planetesimals as the origin of warm dust around a Sun-like star p363
Inseok Song, B. Zuckerman, Alycia J. Weinberger and E. E. Becklin
doi: 10.1038/nature03853
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Seismic resurfacing by a single impact on the asteroid 433 Eros p366
P. C. Thomas and Mark S. Robinson
doi: 10.1038/nature03855
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Massively parallel manipulation of single cells and microparticles using optical images p370
Pei Yu Chiou, Aaron T. Ohta and Ming C. Wu
doi: 10.1038/nature03831
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Direct observation of electron dynamics in the attosecond domain p373
A. F?hlisch, P. Feulner, F. Hennies, A. Fink, D. Menzel, D. Sanchez-Portal, P. M. Echenique and W. Wurth
doi: 10.1038/nature03833
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Spin transition of iron in magnesiowüstite in the Earth's lower mantle p377
Jung-Fu Lin, Viktor V. Struzhkin, Steven D. Jacobsen, Michael Y. Hu, Paul Chow, Jennifer Kung, Haozhe Liu, Ho-kwang Mao and Russell J. Hemley
doi: 10.1038/nature03825
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The long-term strength of Europe and its implications for plate-forming processes p381
M. Pérez-Gussinyé and A. B. Watts
doi: 10.1038/nature03854
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Reinforcement of pre-zygotic isolation and karyotype evolution in Agrodiaetus butterflies p385
Vladimir A. Lukhtanov, Nikolai P. Kandul, Joshua B. Plotkin, Alexander V. Dantchenko, David Haig and Naomi E. Pierce
doi: 10.1038/nature03704
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Deep sub-seafloor prokaryotes stimulated at interfaces over geological time p390
R. John Parkes, Gordon Webster, Barry A. Cragg, Andrew J. Weightman, Carole J. Newberry, Timothy G. Ferdelman, Jens Kallmeyer, Bo B. J?rgensen, Ivano W. Aiello and John C. Fry
doi: 10.1038/nature03796
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Male-specific fruitless specifies the neural substrates of Drosophila courtship behaviour p395
Devanand S. Manoli, Margit Foss, Adriana Villella, Barbara J. Taylor, Jeffrey C. Hall and Bruce S. Baker
doi: 10.1038/nature03859
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EphrinB2 is the entry receptor for Nipah virus, an emergent deadly paramyxovirus p401
Oscar A. Negrete, Ernest L. Levroney, Hector C. Aguilar, Andrea Bertolotti-Ciarlet, Ronen Nazarian, Sara Tajyar and Benhur Lee
doi: 10.1038/nature03838
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Regulation of Mycobacterium tuberculosis cell envelope composition and virulence by intramembrane proteolysis p406
Hideki Makinoshima and Michael S. Glickman
doi: 10.1038/nature03713
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Trans-SNARE pairing can precede a hemifusion intermediate in intracellular membrane fusion p410
Christoph Reese, Felix Heise and Andreas Mayer
doi: 10.1038/nature03722
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Structural basis of family-wide Rab GTPase recognition by rabenosyn-5 p415
Sudharshan Eathiraj, Xiaojing Pan, Christopher Ritacco and David G. Lambright
doi: 10.1038/nature03798
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Chloride/proton antiporter activity of mammalian CLC proteins ClC-4 and ClC-5 p420
Alessandra Picollo and Michael Pusch
doi: 10.1038/nature03720
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Voltage-dependent electrogenic chloride/proton exchange by endosomal CLC proteins p424
Olaf Scheel, Anselm A. Zdebik, Stéphane Lourdel and Thomas J. Jentsch
doi: 10.1038/nature03860
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SUMO-modified PCNA recruits Srs2 to prevent recombination during S phase p428
Boris Pfander, George-Lucian Moldovan, Meik Sacher, Carsten Hoege and Stefan Jentsch
doi: 10.1038/nature03665
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Top of pageNaturejobs
Prospect
A tangential route to success p435
Young scientist follows a bench tangent to biotech success
Paul Smaglik
doi: 10.1038/nj7049-435a
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Postdocs and Students
Learning to mentor p436
Having a good mentor can determine the direction and probability of success for a young researcher. But mentoring takes skill, and institutions are paying attention to their training, says Virginia Gewin.
Virginia Gewin
doi: 10.1038/nj7049-436a
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Career Views
Giovanni Galizia, professor of neurobiology, University of Konstanz, Germany p438
German scientist coming home from California
Giovanni Galizia
doi: 10.1038/nj7049-438a
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Scientists & Societies p438
Swedish scientists seek strength in numbers
Marita Ter?s
doi: 10.1038/nj7049-438b
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Graduate Journal: A study in time p438
Graduate experience warps time
Anne Margaret Lee
doi: 10.1038/nj7049-438c
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Futures
Don't mention the 'F' word p440
Raising brows.
Neil Mathur
doi: 10.1038/436440a
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