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5月6日Nature中文摘要

(选自英国Nature杂志,2010年5月6日出版)


封面故事: 交替剪接的预测
Deciphering the splicing code
脊椎动物基因组的编码能力通过交替剪接大大增强,这使单个基因能够产生一个以上截然不同的蛋白。交替剪接决定遗传信息如何控制细胞过程,而很多人类疾病突变都影响剪接。能够从基因组序列数据预测不同交替剪接的信使RNA的表达,是基因表达领域人们所长期追寻的一个目标。多伦多大学Frey 和 Blencowe实验室合作开发出一种“剪接代码”,它能准确预测数百个RNA特征是怎样协同工作来调控数千个外显子依赖于组织的交替剪接的。这个代码已被用来预测交替剪接在发育和神经过程中会怎样发挥重要作用,并且为了解剪接调控的机制提供了线索。该代码还被集成到了一个网络工具中,它使研究人员能够扫描未定性的外显子和内显子序列,预测依赖于组织的剪接模式。(Article p. 53; News & Views)封面图片:Brendan Frey


应对感官刺激的神经编码(Neuronal coding)
Olfactory pattern classification by discrete neuronal network states
在对感官刺激做出反应时,大脑被认为会将这些刺激分成不相关联的认知类别,但其中所涉及的神经机制仍不清楚。Jörn Niessing 和 Rainer Friedrich通过利用双质子钙成像来监测曝露于各种不同浓度的一系列气味分子的斑马鱼嗅球中发射(激发)速度的变化情况,对这一现象进行了研究。在有一系列逐渐变化的气味存在的情况下,当从一种气味向另一种切换时,神经发射(激发)模式会发生突变。气味浓度的变化几乎没有影响。这些结果与关于神经回路的离散状态的“Attractor”网络模型(所预测的情况)是一致的,这些模型也许可以延伸到其他感觉及认知过程。(Article p. 47)


超亮红外星系中分子氢来源另解(Thinking outside the galaxy)
H2 emission arises outside photodissociation regions in ultraluminous infrared galaxies
斯皮策太空望远镜对超亮红外星系的观测结果表明,这些天体中分子氢(H2)的发射(经常被认为是恒星形成活动的一个指标)不是来自这些星系内隐埋的星暴活动,而是来自这些多尘中央区域的外边。这些星系是近域宇宙中最亮天体之一,被认为是由强烈恒星形成活动提供动力的。然而,由Nadia Zakamska获得的这些新的观测结果却指出了H2的另一个来源。Zakamska提出,H2发射是由周围物种中的振动产生的,它们是被与附近星系的相互作用激发的。(Letter p. 60)


能够模仿肌肉的人造蛋白(Muscle mimickry)
Designed biomaterials to mimic the mechanical properties of muscles
Shanshan Lv等人将已经被研究得非常透彻的人造弹性蛋白GB1与节肢弹性蛋白(昆虫身上的一种蛋白)结合起来,生成了能够模仿肌联蛋白(一种主要控制肌肉的被动弹性性质的蛋白)的人造蛋白。这些新的人造蛋白集结构域和非结构域于一体,能够交联成固体。这样所产生的生物材料在受力较低时是有弹性的,在受力较高时是可以延展的和坚韧的,从而模仿肌肉的被动性质,并使其潜在适用于组织工程中,用作人造肌肉的骨架和基质。这是在单分子层面上通过工程方法对一种材料的宏观性质进行量体裁衣的一个例子。(Letter p. 69; News & Views)


地球外核磁场强度的预测(Earth’s core strength)

Fast torsional waves and strong magnetic field within the Earth’s core
没有办法对处于流体状态的地球外核(它产生我们能够测量的磁场)内的磁场进行直接测量。计算内部磁场强度的间接方法所产生的结果是矛盾的。在为期60年的时间里对地球一天的长度所做的观察结果,被用来估计地球内部的磁场强度,所获得的估计值只有约0.2 毫特斯拉;而“地球发电机”数值模型所预测的结果却要比这个数字大一个数量级。现在,Nicolas Gillet 和 colleagues利用地核内液流模型解决了这一偏差。他们所关注的是“准地转振荡”中一个未能解释的峰,这个峰出现在6年左右的时间点上,它是由地核与其外面的固体地幔之间角动量的内部交流所产生的快速扭转波生成的。据此,他们估计外核磁场强度为大约4毫特斯拉,这个结果与“地球发电机”模拟所做预测是一致的。(Letter p. 74; News & Views)


防止mtDNA疾病在人类中传播的方法(mtDNA replacement)
Pronuclear transfer in human embryos to prevent transmission of mitochondrial DNA disease
从母亲传给后代的线粒体DNA(mtDNA)突变是遗传疾病的一个常见原因,会造成神经、肌肉和心脏等方面的问题以及失聪和2-型糖尿病等。研究人员最近在非人灵长类动物中发现,核转移技术可防止它们传播。现在,“原理证明”工作被延伸到了人类胚胎(请参考相关News文章,网址:go.nature.com/xqgWXf)。英国纽卡斯尔大学一个多科系研究小组在人类合子(受精卵)之间进行了原核(前核)转移,并在试管中实现了向胚泡阶段的发育。供体合子mtDNA的转移是很少的,所以该方法有可能防止mtDNA疾病在人类中的传播。(Letter p. 82)


果蝇用来检测水味道的受体(A taste for water)
The molecular basis for water taste in Drosophila
动物必须能够在它们环境中找到水才能生存,但它们是怎样做到这一点的却仍不清楚。现在,作为退化蛋白/上皮钠通道家族中一员的PPK28,被发现是果蝇的水味道受体。这个家族的其他蛋白已经被发现与机械刺激和盐刺激的检测有关。(Letter p. 91)


用于治疗丙肝的新药(New drugs for hepatitis C)
Chemical genetics strategy identifies an HCV NS5A inhibitor with a potent clinical effect
临床上必需的用来治疗慢性丙肝病毒(HCV)感染的直接作用抗病毒药物的研制,一直主要以两种病毒酶的抑制因子为关注焦点,它们分别是蛋白酶NS3 和 NS5B(HCV复制所需要的一种依赖于RNA的RNA聚合酶)。BMS-790052(用化学遗传学方法确定为一种强效特异性HCV抑制因子)是没有已知酶活性的第三种病毒分子(即非结构性蛋白5A,简称为“NS5A”)的一个小分子抑制因子。来自“百时美施贵宝公司”的一个研究小组在本期Nature上报告了BMS-790052的发现及其病毒特征,披露了用这一化合物在正常的健康志愿者和HCV感染者中所进行的临床试验观察结果。这些临床结果确立了对HCV NS5A抑制作为一种临床相关机制的概念证明。试管试验数据表明(该药物)与已知的HCV抑制药物之间有协同作用效果,说明抗病毒药物的混配(即所谓的“鸡尾酒”方法)也许是一个可行的治疗方式。(Letter p. 96)


酵母细胞交配前的决策过程(Speed dating in yeast)

The scaffold protein Ste5 directly controls a switch-like mating decision in yeast
在交配前,一个酿酒酵母细胞必须在其附近检测表达大量某种性信息素的一个伙伴细胞。这个信息素检测系统涉及MAP激酶信号传导级联,而分泌最高浓度信息素的潜在伙伴就是被选择的交配对象。一项将实验和数学模拟相结合的研究工作表明,交配决策是一种所谓的“all-or-none”开关式响应:要使交配开始,酵母细胞周围的信息素必须达到一个临界浓度,而如果这个浓度达不到,酵母细胞将继续进行无性繁殖。这种决策的做出是很快的,在与一种信息素最初接触2分钟内就能完成。骨架蛋白Ste5(它在一个活性复合物中结合MAPK级联成分)是信息素的作用的直接调控因子。如果相似的超灵敏机制出现在哺乳动物信号作用通道中,它们面对导致疾病的突变也许会尤为脆弱,因此可能会被证明是重要的治疗目标。(Letter p. 101)


植物能在黑暗中变绿之谜(Dark greening materials)

X-ray crystal structure of the light-independent protochlorophyllide reductase
一些光合作用生物(例如松苗和其他裸子植物)能够在黑暗中变绿,这与豌豆等被子植物幼苗变绿对光的严格要求形成对比。这种“黑暗艺术”背后的酶是在黑暗中发挥作用的“原叶绿素酸脂(Pchlide)氧化还原酶”(DPOR),它催化Pchlide的C17-C18双键的立体选择性还原,生成叶绿素酸酯-a(叶绿素-a的直接前体)。现在,来自紫色光养菌Rhodobacter capsulatus的DPOR的NB-蛋白部分的晶体结构已被确定。该结构显示了Pchlide 的C17-C18双键还原反应的一个可能的化学机制。有趣的是,DPOR与众所周知的固氮酶相似,说明固氮的分子机制与在黑暗中产生叶绿素的分子机制之间存在一个密切的演化关系。(Letter p. 110)




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EDITORIALS
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A plan for the ocean p9
Governments have typically regulated their coastal waters as if fishing,
shipping and the like were separate entities. A new, integrated approach
could change all that - while greatly boosting marine science.
doi:10.1038/465009a
http://www.nature.com/nature/journal/v465/n7294/full/465009a.html

Up in the air pp9-10
Ways to obtain more accurate data can and should be put in place to police
greenhouse-gas emissions.
doi:10.1038/465009b
http://www.nature.com/nature/journal/v465/n7294/full/465009b.html

Open to all p10
A new approach to technology assessment would supplement expert opinion
with input from society.
doi:10.1038/465010a
http://www.nature.com/nature/journal/v465/n7294/full/465010a.html

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RESEARCH HIGHLIGHTS
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Ecology: Not-so-lonesome lizards p12
doi:10.1038/465012a
http://www.nature.com/nature/journal/v465/n7294/full/465012a.html

Neuroscience: What makes masculinity? p12
doi:10.1038/465012b
http://www.nature.com/nature/journal/v465/n7294/full/465012b.html

Oceanography: Deep-sea biomass boom p12
doi:10.1038/465012c
http://www.nature.com/nature/journal/v465/n7294/full/465012c.html

Atmospheric science: Ozone high and low p12
doi:10.1038/465012d
http://www.nature.com/nature/journal/v465/n7294/full/465012d.html

Microscopy: See through tissue p12
doi:10.1038/465012e
http://www.nature.com/nature/journal/v465/n7294/full/465012e.html

Genomics: Rat sequencing redux pp12-13
doi:10.1038/465012f
http://www.nature.com/nature/journal/v465/n7294/full/465012f.html

Drug development: Virus knockdown p13
doi:10.1038/465013a
http://www.nature.com/nature/journal/v465/n7294/full/465013a.html

Optical devices: Organic light p13
doi:10.1038/465013b
http://www.nature.com/nature/journal/v465/n7294/full/465013b.html

Microbiology: Bacterial break up p13
doi:10.1038/465013c
http://www.nature.com/nature/journal/v465/n7294/full/465013c.html

Cognitive neuroscience: Attention please! p13
doi:10.1038/465013d
http://www.nature.com/nature/journal/v465/n7294/full/465013d.html

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JOURNAL CLUB
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Journal club p13
James Noonan
doi:10.1038/465013e
http://www.nature.com/nature/journal/v465/n7294/full/465013e.html


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NEWS
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News briefing: 6 May 2010 pp14-15
The week in science
doi:10.1038/465014a
http://www.nature.com/nature/journal/v465/n7294/full/465014a.html

The code within the code pp16-17
Computational biologists grapple with RNA's complexity.
Heidi Ledford
doi:10.1038/465016a
http://www.nature.com/news/2010/100505/full/465016a.html

Nurse wants elite UK science focus pp16-17
Incoming head of Royal Society sets out his agenda.
Geoff Brumfiel
doi:10.1038/465016b
http://www.nature.com/news/2010/100430/full/465016b.html

Greenhouse-gas numbers up in the air pp18-19
To control emissions, countries must first account accurately for their
carbon. That will take considerable effort, reports Jeff Tollefson.
Jeff Tollefson
doi:10.1038/465018a
http://www.nature.com/nature/journal/v465/n7294/full/465018a.html

Green patents corralled p21
Quirin Schiermeier
doi:10.1038/465021a
http://www.nature.com/nature/journal/v465/n7294/full/465021a.html

Greeks hope crisis may spark reform pp22-22
Financial troubles could be the stimulus for a fairer distribution of
science research funding.
Alison Abbott
doi:10.1038/465022a
http://www.nature.com/news/2010/100504/full/465022a.html

European funding may get simpler pp22-22
Research commissioner promises to cut red tape in framework programmes.
Alison Abbott
doi:10.1038/465022b
http://www.nature.com/news/2010/100504/full/465022b.html

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NEWS FEATURES
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Seismology: The biggest one pp24-25
Fifty years ago this month, a massive earthquake in Chile broke new
ground in seismic science. Roff Smith looks back at the largest quake ever recorded.
Roff Smith
doi:10.1038/465024a
http://www.nature.com/news/2010/100505/full/465024a.html

Neuroscience: Illuminating the brain pp26-28
Systems neuroscientists are pushing aside their electrophysiology rigs
to make room for the tools of 'optogenetics'. Lizzie Buchen reports from
a field in the process of reinvention.
Lizzie Buchen
doi:10.1038/465026a
http://www.nature.com/news/2010/100505/full/465026a.html

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COLUMN
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World view: Brick by brick pp29-29
A small non-profit organization shows how to reduce the vulnerability of
poor countries to earthquakes, says Daniel Sarewitz.
Daniel Sarewitz
doi:10.1038/465029a
http://www.nature.com/news/2010/100505/full/465029a.html

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CORRESPONDENCE
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OPINION
European money could end delays on essential facilities p31
Massimo Altarelli
doi:10.1038/465031a
http://www.nature.com/nature/journal/v465/n7294/full/465031a.html

Independent research offers freedom and opportunities p31
Bernt Christian Skottun
doi:10.1038/465031b
http://www.nature.com/nature/journal/v465/n7294/full/465031b.html

Earthquake defence and the price of a telescope p31
Leopoldo Infante and Juan Carlos de la Llera
doi:10.1038/465031c
http://www.nature.com/nature/journal/v465/n7294/full/465031c.html

Questionable value of planting thirsty trees in dry regions p31
Shixiong Cao, Guosheng Wang and Li Chen
doi:10.1038/465031d
http://www.nature.com/nature/journal/v465/n7294/full/465031d.html

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OPINION
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Financial pain should focus universities pp32-33
The tightening of the US science budgets could improve both teaching and
research, argues Diane Auer Jones - by forcing academics and their
institutions to play to their strengths.
Diane Auer Jones
doi:10.1038/465032a
http://www.nature.com/nature/journal/v465/n7294/full/465032a.html

Reflections on the ozone hole pp34-35
Jonathan Shanklin, one of the team who discovered the thinning ozone
layer over the Antarctic 25 years ago, reflects on lessons learned from
 a tale of luck, public perception and fast environmental change.
Jonathan Shanklin
doi:10.1038/465034a
http://www.nature.com/nature/journal/v465/n7294/full/465034a.html

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BOOKS AND ARTS
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OPINION
Chemistry's visual origins p36
Vivid imagination was key to unlocking the secrets of molecular structure
in the nineteenth century, finds Andrew Robinson.
Andrew Robinson reviews Image and Reality: Kekule, Kopp, and the Scientific
Imagination by Alan J. Rocke
doi:10.1038/465036a
http://www.nature.com/nature/journal/v465/n7294/full/465036a.html

Managing career moves p37
Peter S. Fiske reviews Chasing Stars: The Myth of Talent and the Portability
of Performance by Boris Groysberg
doi:10.1038/465037a
http://www.nature.com/nature/journal/v465/n7294/full/465037a.html

Medical treasures on show p37
Marta Paterlini reviews Lake Konst (Art of Medicine) by
doi:10.1038/465037b
http://www.nature.com/nature/journal/v465/n7294/full/465037b.html

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NEWS AND VIEWS
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Geophysics: A new turn for Earth's rotation pp39-40
Earth's spin rate varies with time. A six-year periodic signal in the planet's
core is partly responsible, and increases the interior magnetic-field
strength to much higher levels than previously thought.
Andy Jackson
doi:10.1038/465039a
http://www.nature.com/nature/journal/v465/n7294/full/465039a.html

Biochemistry: Getting the metal right pp40-41
Controversy has raged over the identity of the metal cofactor of membrane-bound
methane monooxygenase, a methane-oxidizing enzyme. A study suggests that
the answer is a cluster of two copper ions.
J. Martin Bollinger Jr
doi:10.1038/465040a
http://www.nature.com/nature/journal/v465/n7294/full/465040a.html

Nonlinear dynamics: Optoelectronic chaos pp41-42
Optoelectronic circuits with delayed feedback provide a convenient bench-top
platform to study a wide range of nonlinear dynamic systems, from ultrastable
clocks to complex chaotic devices.
Laurent Larger and John M. Dudley
doi:10.1038/465041a
http://www.nature.com/nature/journal/v465/n7294/full/465041a.html

Hepatitis C: An unsuspected drug target pp42-44
Infection with hepatitis C is one of the main causes of liver disease, yet
there are no broadly effective treatments. Discovery of a potent inhibitor
of this virus shows that researchers must think outside the box.
Catherine L. Murray and Charles M. Rice
doi:10.1038/465042a
http://www.nature.com/nature/journal/v465/n7294/full/465042a.html

50 & 100 years ago p43
doi:10.1038/465043a
http://www.nature.com/nature/journal/v465/n7294/full/465043a.html

Materials science: Muscle mimic pp44-45
An elastic polymer has been made whose molecular structure mimics that of
titin, a protein found in muscle. The resulting material is tough, stretchy
and dissipates energy ― just like muscle itself.
Elliot L. Chaikof
doi:10.1038/465044a
http://www.nature.com/nature/journal/v465/n7294/full/465044a.html

Gene regulation: Breaking the second genetic code pp45-46
Diverse messenger RNAs, and thus proteins, can be generated from a single
piece of DNA. A computational approach is helping to uncover complex
combinatorial rules by which specific gene instructions are selected.
J. Ramo'n Tejedor and Juan Valca'rcel
doi:10.1038/465045a
http://www.nature.com/nature/journal/v465/n7294/full/465045a.html

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ADDENDUM
----------------------
Addendum p46
doi:10.1038/465046a
http://www.nature.com/nature/journal/v465/n7294/full/465046a.html

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ARTICLES
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Olfactory pattern classification by discrete neuronal network states pp47-52
The brain is apt to sort sensory stimuli into discrete perceptual categories,
but the neuronal activity behind this capability has been unclear. Here, the
problem has been investigated by presenting zebrafish with different
concentrations or types of odours. The results show that the activity of
neuronal populations in the olfactory bulb is largely insensitive to changes
in odour concentration, but that morphing one odour into another produces abrupt
transitions between odour representations.
Jorn Niessing and Rainer W. Friedrich
doi:10.1038/nature08961
Abstract: http://www.nature.com/nature/journal/v465/n7294/abs/nature08961.html
Article: http://www.nature.com/nature/journal/v465/n7294/full/nature08961.html

Deciphering the splicing code pp53-59
The coding capacity of the genome is greatly expanded by the process of
alternative splicing, which enables a single gene to produce more than one
distinct protein. Can the expression of these different proteins be predicted
from sequence data? Here, modelling based on information theory has been used
to develop a 'splicing code', which can predict, with good accuracy,
tissue-dependent changes in alternative splicing.
Yoseph Barash et al.
doi:10.1038/nature09000
Abstract: http://www.nature.com/nature/journal/v465/n7294/abs/nature09000.html
Article: http://www.nature.com/nature/journal/v465/n7294/full/nature09000.html

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LETTERS
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H2 emission arises outside photodissociation regions in ultraluminous infrared
galaxies pp60-63
Ultraluminous infrared galaxies are among the most luminous objects in the local
Universe and are thought to be powered by intense star formation. In these objects,
the rotational lines of molecular hydrogen (H2) observed at mid-infrared
wavelengths are not affected by dust obscuration, but the source of excitation
has been unknown. Here it is found that H2 emission originates outside the
obscured regions; it is proposed that H2 emission traces shocks in the
surrounding material that are excited by interactions with nearby galaxies.
Nadia L. Zakamska
doi:10.1038/nature09037
Abstract: http://www.nature.com/nature/journal/v465/n7294/abs/nature09037.html
Article: http://www.nature.com/nature/journal/v465/n7294/full/nature09037.html

Phase-preserving amplification near the quantum limit with a Josephson ring
modulator pp64-68
Recent progress in solid-state quantum information processing has stimulated
the search for amplifiers and frequency converters with quantum-limited
performance in the microwave range. Here, a phase-preserving, superconducting
parametric amplifier with ultra-low-noise properties has been experimentally realized.
N. Bergeal et al.
doi:10.1038/nature09035
Abstract: http://www.nature.com/nature/journal/v465/n7294/abs/nature09035.html
Article: http://www.nature.com/nature/journal/v465/n7294/full/nature09035.html

Designed biomaterials to mimic the mechanical properties of muscles pp69-73
Here, artificial proteins are described that mimic the molecular architecture of
titin - a protein that helps to govern the passive elastic properties of muscle.
The new artificial proteins combine structured and unstructured domains, and can
be photochemically crosslinked into a solid biomaterial that is resilient at
low strains and extensible and tough at high strains. This provides an example
of tailoring the macroscopic properties of a material through engineering at
the single-molecule level.
Shanshan Lv et al.
doi:10.1038/nature09024
Abstract: http://www.nature.com/nature/journal/v465/n7294/abs/nature09024.html
Article: http://www.nature.com/nature/journal/v465/n7294/full/nature09024.html

Fast torsional waves and strong magnetic field within the Earth’s core pp74-77
The magnetic field inside the Earth's outer core cannot be directly probed.
The intensity of the magnetic field at the core-mantle boundary is estimated
to be 0.3 mT, and geodynamo models predict a value about ten times larger
(3 mT) for the core's interior. Other data, however, indicate an internal
field of only around 0.2 mT. This discrepancy has now been resolved: an
ensemble inversion of core flow models finds a torsional wave recurring
every 6 years, leading to an estimated field strength of around 4 mT inside the core.
Nicolas Gillet, Dominique Jault, Elisabeth Canet and Alexandre Fournier
doi:10.1038/nature09010
Abstract: http://www.nature.com/nature/journal/v465/n7294/abs/nature09010.html
Article: http://www.nature.com/nature/journal/v465/n7294/full/nature09010.html

Seismic and aseismic slip on the Central Peru megathrust pp78-81
Slip on a subduction megathrust can occur during an earthquake or aseismically.
The size, location and frequency of earthquakes that a megathrust can generate
depend on where and when aseismic creep is taking place, and what fraction of
the long-term slip it accounts for. Here this issue is addressed by looking at
the central Peru megathrust, and specifically at the Pisco earthquake of
2007. The findings show that aseismic creep accounts for 50-70% of the slip
budget on the seismogenic portion of the megathrust.
Hugo Perfettini et al.
doi:10.1038/nature09062
Abstract: http://www.nature.com/nature/journal/v465/n7294/abs/nature09062.html
Article: http://www.nature.com/nature/journal/v465/n7294/full/nature09062.html

Pronuclear transfer in human embryos to prevent transmission of mitochondrial
DNA disease pp82-85
Mutations in mitochondrial DNA (mtDNA) are a common cause of human genetic
disease. It has been shown in non-human primates that nuclear transfer
techniques might be an approach to prevent the transmission of mtDNA mutations.
The proof of principle has now been extended to human embryos. Pronuclei
were transferred between human zygotes, which developed onwards to the
blastocyst stage in vitro. Carry-over of mtDNA from the donor zygotes to
the recipients was minimal.
Lyndsey Craven et al.
doi:10.1038/nature08958
Abstract: http://www.nature.com/nature/journal/v465/n7294/abs/nature08958.html
Article: http://www.nature.com/nature/journal/v465/n7294/full/nature08958.html

Cis-interactions between Notch and Delta generate mutually exclusive signalling
states pp86-90
Notch and Delta are transmembrane proteins that allow neighbouring cells to
communicate during development. Here, quantitative time-lapse microscopy has
been used to show that the response of Notch to Delta on a neighbouring
cell is graded, whereas its response to Delta on the same cell is sharp
and occurs at a fixed threshold. A mathematical model explores how this
new design principle enhances the sharpness of developmental boundaries
set by classical lateral inhibition.
David Sprinzak et al.
doi:10.1038/nature08959
Abstract: http://www.nature.com/nature/journal/v465/n7294/abs/nature08959.html
Article: http://www.nature.com/nature/journal/v465/n7294/full/nature08959.html

The molecular basis for water taste in Drosophila pp91-95
Animals must detect water in their environment to stay alive, but the molecular
basis for water detection has been unclear. Here the essential mediators of
water-sensing and drinking in fruitflies have been identified: an ion channel
of the degenerin/epithelial sodium channel family, and the sensory neurons that make it.
Peter Cameron, Makoto Hiroi, John Ngai and Kristin Scott
doi:10.1038/nature09011
Abstract: http://www.nature.com/nature/journal/v465/n7294/abs/nature09011.html
Article: http://www.nature.com/nature/journal/v465/n7294/full/nature09011.html

Chemical genetics strategy identifies an HCV NS5A inhibitor with a potent
clinical effect pp96-100
Almost 200 million people worldwide are chronically infected with hepatitis C
virus. Current treatments are poorly tolerated and not wholly effective, so
new drugs are needed. Here, a potent new inhibitor of hepatitis C virus is
described. This inhibitor targets the viral protein NS5A, and shows potential
as part of a therapeutic regimen based on a combination of viral inhibitors.
Min Gao et al.
doi:10.1038/nature08960
Abstract: http://www.nature.com/nature/journal/v465/n7294/abs/nature08960.html
Article: http://www.nature.com/nature/journal/v465/n7294/full/nature08960.html

The scaffold protein Ste5 directly controls a switch-like mating decision in
yeast pp101-105
Before mating, a yeast cell must detect a partner cell that is close enough
and expresses sufficiently large amounts of a sex pheromone. The mating
decision is an all-or-none, switch-like response to pheromone concentration.
It is now shown that this decision involves the competition of one kinase and
one phosphatase enzyme for multiple phosphorylation sites on a 'scaffold'
protein. The results should prompt a re-evaluation of the role of related
signalling molecules that have been implicated in cancer.
Mohan K. Malleshaiah, Vahid Shahrezaei, Peter S. Swain and Stephen W. Michnick
doi:10.1038/nature08946
Abstract: http://www.nature.com/nature/journal/v465/n7294/abs/nature08946.html
Article: http://www.nature.com/nature/journal/v465/n7294/full/nature08946.html

An RNA polymerase II- and AGO4-associated protein acts in RNA-directed DNA
methylation pp106-109
DNA methylation is an important epigenetic mark in many eukaryotes. In
Arabidopsis plants, small interfering RNAs bound to the Argonaute 4 (AGO4)
protein can direct de novo DNA methylation and consequent gene silencing.
Here, a new regulator of RNA-directed DNA methylation has been discovered.
This protein, RDM1, is proposed to bind to methylated DNA and to function
in the AGO4 effector complex.
Zhihuan Gao et al.
doi:10.1038/nature09025
Abstract: http://www.nature.com/nature/journal/v465/n7294/abs/nature09025.html
Article: http://www.nature.com/nature/journal/v465/n7294/full/nature09025.html

X-ray crystal structure of the light-independent protochlorophyllide reductase
The ability of plants to 'green' in the dark is attributed to the activity of
the dark-operative protochlorophyllide oxidoreductase (DPOR). This enzyme
catalyses the stereospecific reduction of the C17[equiv]C18 double bond of
protochlorophyllide to form chlorophyllide a, the direct precursor of
chlorophyll a. The X-ray crystal structure of the catalytic component of
DPOR has now been solved. A chemical mechanism is proposed by which the
reduction of the double bond may occur.
Norifumi Muraki et al.
doi:10.1038/nature08950
Abstract: http://www.nature.com/nature/journal/vaop/ncurrent/full/nature08950.html
Article: http://www.nature.com/nature/journal/vaop/ncurrent/full/nature08950.html

Oxidation of methane by a biological dicopper centre pp115-119
Particulate methane monooxygenase (pMMO) is an integral membrane protein,
found in methanotropic bacteria, that can selectively oxidize methane to
produce methanol. This metalloenzyme contains three subunits, and the metal
composition and exact location of its active site has been the subject of
much speculation. Here it is found that the enzyme's activity is dependent
on copper, and that the active site is located in the soluble domains of the pmoB subunit.
Ramakrishnan Balasubramanian et al.
doi:10.1038/nature08992
Abstract: http://www.nature.com/nature/journal/v465/n7294/abs/nature08992.html
Article: http://www.nature.com/nature/journal/v465/n7294/full/nature08992.html

----------------------
CORRIGENDUM
----------------------
Genome sequence of the palaeopolyploid soybean p120
Jeremy Schmutz et al.
doi:10.1038/nature08957
http://www.nature.com/nature/journal/v465/n7294/full/nature08957.html

----------------------
FUTURES
----------------------
KYLE 7 p126
Virtual success.
Giulio Zambon
doi:10.1038/465126a
http://www.nature.com/nature/journal/v465/n7294/full/465126a.html

 

 
    
 


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