Tạp chí khoa học số 2006-12-01

1 December 2006 | $10 Our new Paq5000 ™ DNA Polymerase * is an economic alternative to Taq that costs only 5 cents per unit. ** This new enzyme provides improved PCR yield with reduced cycling time and is ideal for routine end-point PCR on targets up to 6 kb (genomic). Furthermore, the Paq5000 DNA polymerase is derived from a Pyrococcus species and comes with an optimized 10X buffer. Switch from Taq to Paq5000 DNA polymerase today! AMPLIF ICATI ON CELL B IOLOG Y C LONING MICROA RRA Y S N UCLEI C A CID A NALYS I S PROTEIN FUNCTION & ANALYSIS QUANTI T ATIVE P CR S OFTWA R E S OLUTI ONS Ask us about these great products: How much is 5¢ really worth? Find out with our new thermostable Paq5000 ™ DNA Polymerase for PCR. Paq5000 ™ DNA Polymerase 500 units 600680 1000 units 600682 5000 units 600684 Call for special pricing on large orders and custom/bulk packaging. * US Patent Nos. 7,045,328, 6,734,293, 6,489,150, 6,444,428, 6,183,997, and 5,489,523. Purchase of this product conveys to the purchaser the non-transferable right under these patents to use the product for research use only. ** Pricing in US Dollars. Pricing valid in US only. For pricing in other countries, please contact your Stratagene sales representative or your local distributor. Paq5000 ™ is a trademark of Stratagene in the United States. Need More Information? Give Us A Call: Stratagene US and Canada Order: 800-424-5444 x3 Technical Service: 800-894-1304 x2 Stratagene Europe Order: 00800-7000-7000 Technical Service: 00800-7400-7400 www.stratagene.com Stratagene Japan K.K. Order: 3-5821-8077 Technical Service: 3-5821-8076 M N N I I R R P P 2.6 kb 900 bp Comparison of genomic DNA amplification using the Paq5000 ™ DNA Polymerase and Taq DNA polymerase from various suppliers (competitors N, I, R, P) using standard conditions. Paq5000 ™ Obtain Equal or Better Yield than Taq DNA Polymerase polymerase GE Healthcare To 100,000 scientists worldwide, ÄKTA ™ sets the standard in protein purification. All systems in the ÄKTA design ™ family work with intelligent UNIC ORN ™ softwar e, which makes it easy to control every stage of your purification process. But we’re never content to stand still. The result is products like ÄKTAxpress ™ , which can solve low expression and double-tagged protein purification challenges, and ÄKTApurifier ™ , a time-saving automated protein purification system that can be configured to suit your personal application and workflow needs. By continually developing technology that can turn your scientific ideas into reality, we’re bringing science to life and helping transform healthcare. We call it Protein Separations Re -imagined. Discover the legendary purification power of UNICORN and ÄKTA , visit www.gehealthcare.com/akta 100,000 scientists working with proteins believe in ÄKTA, UNICORN and wizards. © 2006 General Electric Company – All rights reserved. GE Healthcare Bio-Sciences AB, a General Electric Company. GE09-06 See also related STKE material on page 1347 or at www.sciencemag.org/sciext/cellsignaling06/ www.sciencemag.org SCIENCE VOL 314 1 DECEMBER 2006 1341 CONTENTS CONTENTS continued >> DEPARTMENTS 1347 Science Online 1349 This Week in Science 1355 Editors’ Choice 1360 Contact Science 1363 Random Samples 1365 Newsmakers 1471 New Products 1472 Science Careers EDITORIAL 1353 Responding to Fraud by Donald Kennedy 1374 1410 INTRODUCTION Size, Mates, and Fates 1409 PERSPECTIVES Brassinosteroid Signaling: A Paradigm for Steroid Hormone 1410 Signaling from the Cell Surface Y. Belkhadir and J. Chory G Protein Signaling in Yeast: New Components, 1412 New Connections, New Compartments J. E. Slessareva and H. G. Dohlman Notch, a Universal Arbiter of Cell Fate Decisions 1414 M. Ehebauer, P. Hayward, A. Martinez-Arias SPECIAL SECTION Cell Signaling Volume 314, Issue 5804 COVER Artist’s representation of communication pathways initiated by cell surface receptors that influence cell physiology and organelle function. This joint special issue between Science and Science’s STKE highlights new insights into signaling mechanisms that control development and reproduction (see page 1409). Image: Christopher Bickel NEWS OF THE WEEK China’s Fraud Buster Hit by Libel Judgments; 1366 Defenders Rally Round Fraud Investigation Clouds Paper on Early Cell Fate 1367 SCIENCESCOPE 1369 Squelching Progesterone’s Signal May Prevent 1370 Breast Cancer >> Report p. 1467 Three Methods Add Up to One New Way to 1371 Genetically Engineer Fruit Flies >> Science Express Report by K. J. T. Venken et al. WHO Panel Weighs Radical Ideas 1373 NEWS FOCUS Doing More With Less 1374 Burst-Hunter’s Rich Data Harvest Yields a 1376 Cosmic Enigma South Africa Bolsters HIV/AIDS Plan, but 1378 Obstacles Remain The Saola’s Last Stand 1380 CONNECTIONS MAPS Brassinosteroid Signaling Pathway Y. Belkhadir, X. Wang, J. Chory Sci. STKE, http://stke.sciencemag. org/cgi/cm/ stkecm;CMP_19131 Arabidopsis Brassinosteroid Signaling Pathway Y. Belkhadir, X. Wang, J. Chory Sci. STKE, http://stke.sciencemag.org/cgi/cm/stkecm;CMP_19349 Pheromone Signaling Pathways in Yeast H. G. Dohlman and J. E. Slessareva Sci. STKE, http://stke.sciencemag.org/cgi/cm/stkecm;CMP_13999 Notch Signaling Pathway M. Ehebauer, P. Hayward, A. Martinez-Arias Sci. STKE, http://stke.sciencemag.org/cgi/cm/stkecm;CMP_19043 FlexiPlate siRNA from QI AGEN is a giant leap forward for more flexible,cost-effective RNAi screening! ■ Maximum flexibility to select siRNAs for human and mouse genes, controls, scales, and 96-well platelayout ■ Economical options allow screening of more target genes within budget ■ Cutting-edge siRNA design minimizes off-target effects and maximizes potency ■ Fast and easy access via QIAGEN’s GeneGlobe ™ Web portal For up-to-date trademarks anddisclaimers, see www .qiagen.com . RNAiFlexiPlate1206S1WW © 2006 QIAGEN, all rights reserved. Systems Biology — RNAi FlexiPlate siRNA — your customized RNAi solution New WWW. QIA GEN . COM Experience maximum flexibility at www.qiagen.com/GeneGlobe ! www.sciencemag.org SCIENCE VOL 314 1 DECEMBER 2006 1343 CONTENTS continued >> SCIENCE EXPRESS www.sciencexpress.org MOLECULAR BIOLOGY P[acman]: A BAC Transgenic Platform for Targeted Insertion of Large DNA Fragments in Drosophila Melanogaster K. J. T. Venken, Y. He, R. A. Hoskins, H. J. Bellen A method allows efficient site-specific integration of large DNA sequences and thus manipulation of proteins in vivo in Drosophila and potentially other organisms. >> News story p. 1371 10.1126/science.1134426 EVOLUTION Homoploid Hybrid Speciation in an Extreme Habitat Z. Gompert, J. A. Fordyce, M. L. Forister, A. M. Shapiro, C. C. Nice As postulated by theory, a new species of butterfly evolved when a hybrid of two existing species became adapted to an extreme alpine environment. 10.1126/science.1135875 GEOPHYSICS Slow Earthquakes Coincident with Episodic Tremors and Slow Slip Events Y. Ito, K. Obara, K. Shiomi, S. Sekine, H. Hirose A series of weak low-frequency earthquakes correspond with seismic tremor and slip episodes on a subduction zone beneath Japan, perhaps increasing overall stress. 10.1126/science.1134454 ASTROPHYSICS Spectropolarimetric Diagnostics of Thermonuclear Supernova Explosions L. Wang, D. Baade, F. Patat A survey of supernovae shows that brighter ones have more spherical explosions, constraining the physics of burning and improving their use as standard candles. 10.1126/science.1121656 LETTERS Balancing Communication and Safety S. A. Ehrlich 1387 Glossing Over the Complexity of Water G. Kallis, M. Kiparsky, A. Milman, I. Ray Mitochondrial DNA and Population Size O. F. Berry; J. P. Wares et al. Response E. Bazin et al. BOOKS ET AL. The Other Insect Societies 1391 J. T. Costa, reviewed by R. Gadagkar The Creation An Appeal to Save Life on Earth 1392 E. O. Wilson, reviewed by S. Bouma-Prediger Nota Bene: Game On Science Museum, London 1393 POLICY FORUM When Patents Threaten Science 1395 L. Andrews, J. Paradise, T. Holbrook, D. Bochneak PERSPECTIVES The Turing Model Comes of Molecular Age 1397 P. K. Maini, R. E. Baker, C M. Chuong >> Report p. 1447 Variable High-Energy γ Rays from the Elliptical 1398 Galaxy M87 A. C. Fabian >> Report p. 1424 When Dry Air Is Too Humid 1399 T. Peter et al. Tools to Tamper with Phosphoinositides 1402 S. McLaughlin >> Reports pp. 1454 and 1458 Delivering New Disease Genes 1403 L. R. Cardon >> Report p. 1461 Edward I. Stiefel (1942–2006) 1406 F. M. M. Morel and J. T. Groves TECHNICAL COMMENT ABSTRACTS EVOLUTION Comment on “Population Size Does Not Influence 1390 Mitochondrial Genetic Diversity in Animals” C. J. Mulligan, A. Kitchen, M. M. Miyamoto full text at www.sciencemag.org/cgi/content/full/314/5804/1390a BREVIA CLIMATE CHANGE Old-Growth Forests Can Accumulate Carbon in Soils 1417 G. Zhou et al. Old-growth forests in Southern China accumulated atmospheric carbon at a rate considerably greater than expected for broadleaved evergreen forests. RESEARCH ARTICLE ATMOSPHERIC SCIENCE Phytoplankton and Cloudiness in the 1419 Southern Ocean N. Meskhidze and A. Nenes Oxidation of aerosols released from a phytoplankton bloom doubled the number of droplets in overlying clouds and reflected solar radiation as much as severe air pollution. REPORTS ASTRONOMY Fast Variability of Tera–Electron Volt γ Rays from 1424 the Radio Galaxy M87 F. Aharonian et al. Very-high-energy gamma rays from the radio galaxy M87 vary daily, implying that they originate close to the central supermassive black hole. >> Perspective p. 1398 PHYSICS Solid-State Qubits with Current-Controlled Coupling 1427 T. Hime et al. Manipulation of the mutual inductance between two qubits can be used to switch their coupling on and off. CONTENTS Good Vibrations Great Sections! ”Ideally, a tissue slicer should generate large-amplitude and high-frequency movements of the cutting blade in a horizontal axis, with minimal vibrations in the vertical axis.“ *(According to Prof. P. Jonas, Institute of Physiology, University of Freiburg, Germany). Leica translated this into the Leica VT1200 and the Leica VT1200 S Vibrating Blade Microtome for cutting fresh and fixed tissues. Designed with You in Mind! * Ref: Pflügers Arch - Eur. J. Physiol. (2002) 443:491-501 Patch-clamp recording in brain slices with improved slicer technology *J.R.P. Geiger - J. Bischofberger - I. Vida - U. Fröbe S. Pfitzinger - H.J. Weber - K. Haverkampf - P. Jonas www.leica-microsystems.com/VT1200 S . Healthcare Bio-Sciences AB, a General Electric Company. GE09-06 See also related STKE material on page 1347 or at www.sciencemag.org/sciext/cellsignaling06/ www.sciencemag.org SCIENCE VOL 314. >> DEPARTMENTS 1347 Science Online 1349 This Week in Science 1355 Editors’ Choice 1360 Contact Science 1363 Random Samples 1365 Newsmakers 1471 New Products 1472 Science Careers EDITORIAL 1353. flexibility at www.qiagen.com/GeneGlobe ! www.sciencemag.org SCIENCE VOL 314 1 DECEMBER 2006 1343 CONTENTS continued >> SCIENCE EXPRESS www.sciencexpress.org MOLECULAR BIOLOGY P[acman]: