Table Of ContentVolume 436 Number 7053 pp889-1064
In this issue (18 August 2005) • Books and Arts
• News and Views
• Editorials • Brief Communications
• Research Highlights • Insight
• News • Article
• News Features • Letters
• Business • Naturejobs
• Correspondence • Futures
• Commentary
Editorials
Science and religion in harmony p889
A spiritual leader with an interest in research has encountered opposition to his plans to speak at a
scientific meeting. But he is perfectly entitled to do so.
Ratings games p889
Researchers have two rare opportunities to influence the ways in which they may be assessed in future.
Climate for progress p890
The painstaking US approach to the assessment of climate-change science yields some useful results.
Research Highlights
Research highlights p892
News
Synthetic biologists face up to security issues p894
Do technological advances need new rules?
Erika Check
NASA draws up blueprint for craft to reach Moon and Mars p895
Mars Society hears plans for shuttle successor
Kendall Powell
Warming debate highlights poor data p896
Studies of troposphere show trends are consistent with warming world.
Jenny Hogan
Climate sceptics place bets on world cooling down p897
Solar physicists make $10,000 wager with climate modeller.
Jim Giles
Sidelines p898
Survey questions safety of alternative medicine p898
Adverse reactions must be monitored, warns expert.
Alison Abbott
WHO urges regional offices to stockpile flu drug for staff p899
Internal plan says obtain drugs for a third of staff.
Declan Butler
Kansas backs lessons critical of evolution p899
School board adopts language from 'intelligent-design' documents.
Geoff Brumfiel
Index aims for fair ranking of scientists p900
'H-index' sums up publication record.
Philip Ball
News in brief p901
News Features
International Space Station: Testing times p902
Preparing astronauts for a journey to the red planet has become NASA's research priority for the
International Space Station. But such experiments will need more than the skeleton crew now running the
station. Tony Reichhardt reports.
I
Complex systems: Order out of chaos p905
Can the behaviour of complex systems from cells to planetary climates be explained by the idea that they're
driven to produce the maximum amount of disorder? John Whitfield investigates.
Deep-sea biology: The life aquatic p908
Cindy Lee Van Dover likes nothing better than to be on the ocean floor. Emma Marris meets the unconventional
biologist who has devoted her life to studying the exotic ecosystems of the deep.
Business
Drug firms back-pedal on direct advertising p910
The pharmaceutical industry is taking a long, hard look at how it promotes its products to the public.
Colin Macilwain reports.
In brief p911
Market watch p911
Correspondence
Buddhism is no bar to an open mind. Is science? p912
Janis L. Dickinson
Power-plant design should prepare for carbon capture p912
Jon Gibbins
Answering the critics of Japanese whale research p912
Hiroshi Hatanaka
Commentary
Re-wilding North America p913
A plan to restore animals that disappeared 13,000 years ago from Pleistocene North America offers an
alternative conservation strategy for the twenty-first century, argue Josh Donlan and colleagues.
Books and Arts
Live long and prosper p915
Science can boost your chance of reaching a healthy old age — but don't hold your breath for immortality.
Tom Kirkwood reviews Fantastic Voyage: Live Long Enough to Live Forever by Ray Kurzweil and Terry Grossman
and The Life Extension Revolution: The New Science of Growing Older Without Aging by Philip Lee Miller
and The Life Extension Foundation (with Monica Reinagel)
Anticlimax p916
Olivia P. Judson reviews The Case of the Female Orgasm: Bias in the Science of Evolution by Elisabeth
A. Lloyd
Science in culture: Prussian precision p917
Anton Hallmann's technical drawings brought geometry to life.
Martin Kemp
News and Views
Biodiversity: Turning up the heat on hotspots p919
Different measures are used to define concentrations of biodiversity — so-called 'hotspots'. More
rigorous, global-scale analyses of how they compare will be essential for efficient resource allocation
to conservation.
Hugh P. Possingham and Kerrie A. Wilson
Cosmology: Original questions p920
The lack of a coherent quantum description of gravity has impeded our understanding of the physics that
determined how the Universe began. A synthesis of recent ideas may take us a step farther back in time.
Martin Bojowald
Atmospheric chemistry: Natural bleach under scrutiny p921
Cosmic rays produce carbon-14, which enters Earth's carbon cycle after being oxidized. It is of great
service to atmospheric chemists in providing a way of tracking the degree to which the atmosphere keeps
itself clean.
Patrick Jöckel and Carl A. M. Brenninkmeijer
Cell biology: Shaggy mouse tales p922
First impressions can be misleading. The enzyme telomerase has been well studied because of its initial
association with cell ageing processes and cancer — but it now seems that this is not all it can do.
Elizabeth H. Blackburn
Astrophysics: Swift progress p923
The agile, choreographed response of the Swift satellite to -ray bursts tests models to an unprecedented
degree. Results from two recent long bursts suggest that the models are good, but require some tweaking.
Dieter H. Hartmann
50 and 100 years ago p924
II
Cardiology: Rips repaired p925
In Duchenne muscular dystrophy, muscle cells die as a result of suffering many tiny membrane ruptures.
A compound that increases membrane resealing can protect heart muscle cells from these effects.
Richard A. Steinhardt
Brief Communications
Conservation biology: Lion attacks on humans in Tanzania p927
Understanding the timing and distribution of attacks on rural communities will help to prevent them.
Craig Packer, Dennis Ikanda, Bernard Kissui and Hadas Kushnir
Brownian motion: Absolute negative particle mobility p928
Alexandra Ros, Ralf Eichhorn, Jan Regtmeier, Thanh Tu Duong, Peter Reimann and Dario Anselmetti
Insight: Hepatitis C - Free access
Produced with support from:
Hepatitis C p929
Ursula Weiss
Unscrambling hepatitis C virus−host interactions p930
Francis V. Chisari
Unravelling hepatitis C virus replication from genome to function p933
Brett D. Lindenbach and Charles M. Rice
Evasion of intracellular host defence by hepatitis C virus p939
Michael Gale, Jr and Eileen M. Foy
Adaptive immune responses in acute and chronic hepatitis C virus infection p946
David G. Bowen and Christopher M. Walker
Challenges and successes in developing new therapies for hepatitis C p953
Raffaele De Francesco and Giovanni Migliaccio
Prospects for a vaccine against the hepatitis C virus p961
Michael Houghton and Sergio Abrignani
Mechanism of action of interferon and ribavirin in treatment of hepatitis C p967
Jordan J. Feld and Jay H. Hoofnagle
Hepatitis C and liver transplantation p973
Robert S. Brown, Jr
Article
Exotoxin A−eEF2 complex structure indicates ADP ribosylation by ribosome mimicry p979
René Jørgensen, A. Rod Merrill, Susan P. Yates, Victor E. Marquez, Adrian L. Schwan, Thomas Boesen
and Gregers R. Andersen
Letters
An unexpectedly rapid decline in the X-ray afterglow emission of long -ray bursts p985
G. Tagliaferri, M. Goad, G. Chincarini, A. Moretti, S. Campana, D. N. Burrows, M. Perri, S. D. Barthelmy,
N. Gehrels, H. Krimm, T. Sakamoto, P. Kumar, P. I. Mészáros, S. Kobayashi, B. Zhang, L. Angelini, P. Banat,
A. P. Beardmore, M. Capalbi, S. Covino, G. Cusumano, P. Giommi, O. Godet, J. E. Hill, J. A. Kennea, V.
Mangano, D. C. Morris, J. A. Nousek, P. T. O'Brien, J. P. Osborne, C. Pagani, K. L. Page, P. Romano, L.
Stella and A. Wells
Young chondrules in CB chondrites from a giant impact in the early Solar System p989
Alexander N. Krot, Yuri Amelin, Patrick Cassen and Anders Meibom
Experimental measurement of the photonic properties of icosahedral quasicrystals p993
Weining Man, Mischa Megens, Paul J. Steinhardt and P. M. Chaikin
Liquid crystal 'blue phases' with a wide temperature range p997
Harry J. Coles and Mikhail N. Pivnenko
Short-term variations in the oxidizing power of the atmosphere p1001
Martin R. Manning, David C. Lowe, Rowena C. Moss, Gregory E. Bodeker and William Allan
In situ Os isotopes in abyssal peridotites bridge the isotopic gap between MORBs and their
source mantle p1005
Olivier Alard, Ambre Luguet, Norman J. Pearson, William L. Griffin, Jean-Pierre Lorand, Abdelmouhcine
Gannoun, Kevin W. Burton and Suzanne Y. O'Reilly
III
Earthquake rupture dynamics frozen in exhumed ancient faults p1009
Giulio Di Toro, Stefan Nielsen and Giorgio Pennacchioni
Silurian brachiopods with soft-tissue preservation p1013
Mark D. Sutton, Derek E. G. Briggs, David J. Siveter and Derek J. Siveter
Global hotspots of species richness are not congruent with endemism or threat p1016
C. David L. Orme, Richard G. Davies, Malcolm Burgess, Felix Eigenbrod, Nicola Pickup, Valerie A. Olson,
Andrea J. Webster, Tzung-Su Ding, Pamela C. Rasmussen, Robert S. Ridgely, Ali J. Stattersfield, Peter
M. Bennett, Tim M. Blackburn, Kevin J. Gaston and Ian P. F. Owens
Local translation of RhoA regulates growth cone collapse p1020
Karen Y. Wu, Ulrich Hengst, Llewellyn J. Cox, Evan Z. Macosko, Andreas Jeromin, Erica R. Urquhart and Samie
R. Jaffrey
Dystrophic heart failure blocked by membrane sealant poloxamer p1025
Soichiro Yasuda, DeWayne Townsend, Daniel E. Michele, Elizabeth G. Favre, Sharlene M. Day and Joseph M.
Metzger
ERM is required for transcriptional control of the spermatogonial stem cell niche p1030
Chen Chen, Wenjun Ouyang, Vadim Grigura, Qing Zhou, Kay Carnes, Hyunjung Lim, Guang-Quan Zhao, Silvia
Arber, Natasza Kurpios, Theresa L. Murphy, Alec M. Cheng, John A. Hassell, Varadaraj Chandrashekar,
Marie-Claude Hofmann, Rex A. Hess and Kenneth M. Murphy
Deficiency of glutaredoxin 5 reveals Fe−S clusters are required for vertebrate haem
synthesis p1035
Rebecca A. Wingert, Jenna L. Galloway, Bruce Barut, Helen Foott, Paula Fraenkel, Jennifer L. Axe, Gerhard
J. Weber, Kimberly Dooley, Alan J. Davidson, Bettina Schmidt, Barry H. Paw, George C. Shaw, Paul Kingsley,
James Palis, Heidi Schubert, Opal Chen, Jerry Kaplan, The Tübingen 2000 Screen Consortium and Leonard
I. Zon
Animal virus replication and RNAi-mediated antiviral silencing in Caenorhabditis elegans
p1040
R. Lu, M. Maduro, F. Li, H. W. Li, G. Broitman-Maduro, W. X. Li and S. W. Ding
RNA interference is an antiviral defence mechanism in Caenorhabditis elegans p1044
Courtney Wilkins, Ryan Dishongh, Steve C. Moore, Michael A. Whitt, Marie Chow and Khaled Machaca
Conditional telomerase induction causes proliferation of hair follicle stem cells p1048
Kavita Y. Sarin, Peggie Cheung, Daniel Gilison, Eunice Lee, Ruth I. Tennen, Estee Wang, Maja K. Artandi,
Anthony E. Oro and Steven E. Artandi
Endonucleolytic processing of covalent protein-linked DNA double-strand breaks p1053
Matthew J. Neale, Jing Pan and Scott Keeney
Naturejobs
Prospect
The lie of the land p1059
More geophysicist PhDs are becoming postdocs
Paul Smaglik
Postdocs and Students
Meeting (to move) up p1060
Scientific conferences give new faculty members a chance to meet the leaders in their field and to give
themselves some much-needed exposure. Kendall Powell works the room.
Kendall Powell
Corrections p1061
Career Views
David Wallace, director, Isaac Newton Institute for Mathematical Sciences, University of
Cambridge p1062
Mathematical approaches can solve career conundrums
David Wallace
Scientists & Societies p1062
Graduate students band together to foster communication
Benno Quade and Ajaybabu Pobbati
Graduate Journal: Master of my fate p1062
Another stage, another choice
Tobias Langenhan
Futures
The bell-curve drug p1064
Choose your poison.
Jim Kling
IV
18.8 Editorial 889 McP 16/8/05 2:57 PM Page 889
www.nature.com/nature Vol 436 |Issue no. 7053|18 August 2005
Science and religion in harmony
A spiritual leader with an interest in research has encountered opposition to his plans to speak at a
scientific meeting. But he is perfectly entitled to do so.
T
he Dalai Lama is due to speak at the annual Society for Neuro- controlling negative emotions, which is a legitimate area for neuro-
science meeting in Washington DC on 12 November, and science research in the future.” But his lecture does not necessarily
some neuroscientists don’t like it (see Nature436,452; 2005). constitute an endorsement of his views by the society.
But the Buddhist leader’s talk is part of a lecture series that the Critics counter that the talk threatens to “entangle the Society for
society is laudably conducting on the science and society — and it Neuroscience with religious activities”. The invitation for the Dalai
should go ahead as planned. Lama to speak will give him a chance to sell his religious beliefs in
The invitation of the Dalai Lama to the meeting will be interpreted the guise of neuroscience, they claim. Their petition opposing the
in some quarters as an insult to his nemesis, China. And, citing the lecture even draws comparisons between the Dalai Lama, with his
oft-repeated refrain that science and religion should be kept sepa- belief in reincarnation, and creationists.
rate, some neuroscientists are calling for the lecture to be cancelled. But speakers at meetings — non-scientists or scientists — should
The critics accuse the Dalai Lama of trying to use the meeting to not be barred on the basis of their religious beliefs. Well-known
sell science that they regard as substandard: research on the rela- scientists including Newton have had religious beliefs that many
tionship between meditation and physiological changes in the brain. people would disagree with, but these have no bearing on the credi-
Even the researchers directly involved in these studies, many of bility of their scientific ideas.
whom are working with the encouragement and support of the Dalai Furthermore, in stark contrast with the approach of most religious
Lama, say that the work is in its early stages. leaders, the Dalai Lama has tried for many years to encourage empir-
But the society did not invite the Dalai Lama to speak as a scien- ical research into the claims he makes for the value of meditation.
tist. He will be in Washington to kick off its lecture series on “Dia- He encourages monks to take
“The Dalai Lama
logues between Neuroscience and Society”, in which non-scientists part in such experiments. Res-
encourages monks to take
are expected to address “subjects of interest to neuroscientists”. The ulting studies have appeared in
second such lecture will be given by Frank Gehry, the architect who respectable scientific journals. part in experiments.
designed the Guggenheim Museum in Bilbao, Spain. It is true that the invitation Resulting studies have
Since Naturefirst reported on this story three weeks ago, several could be interpreted as an insult appeared in respectable
neuroscientists have written to us criticizing efforts to stop the to China. But the manner in
scientific journals.”
lecture (see page 912, for example). It seems reasonable to assume which it was issued — by a sci-
that a fair number of the 30,000 delegates expected to attend one of entist who was attending a meeting on neuroplasticity at the Dalai
the world’s largest scientific meetings will be interested to hear what Lama’s home in India — implies that the neuroscience society
the Dalai Lama has to say. harbours no such intent.
The Dalai Lama will not be a complete outsider at the meeting. It is not unreasonable for the researchers who object to the invita-
Through the Colorado-based Mind & Life Institute, he has already tion to protest against it, and to seek to draw attention to the limita-
interacted with many reputable neuroscientists. According to the tions of the Dalai Lama’s credentials as a speaker. But now that the
society, he was invited, in part, because “he has already had an influ- point has been made, they should withdraw their threatened boycott
ence on the design of experiments of great interest to neuroscien- of the meeting, and instead raise their issues in the open forum that
tists”. As even one opponent of the talk admits: “He has views on will follow his talk. ■
Ratings games Against that background, two new efforts to tackle the challenge
deserve readers’ attention and feedback. One, a citations metric, has
the virtue of focusing explicitly on a researcher’s cumulative citation
Researchers have two rare opportunities to influence achievements. The other, the next UK Research Assessment Exer-
the ways in which they may be assessed in future. cise, is rooted in a deeper, more qualitative assessment, but feeds into
a numerical rating of university departments, the results of which
H
ow to judge the performance of researchers? Whether one is hang around the necks of the less successful for years.
assessing individuals or their institutions, everyone knows Can there be a fair numerical measure of a researcher’s achieve-
that most citation measures, while alluring, are overly sim- ments? Jorge Hirsch, a physicist at the University of California, San
plistic. Unsurprisingly, most researchers prefer an explicit peer Diego, believes there can. He has thought about the weaknesses
assessment of their work. Yet those same researchers know how of current attempts to use citations — total counts of citations, aver-
time-consuming peer assessment can be. aged or peak citations, or counts of papers above certain citation
889
© 2005 Nature PublishingGroup
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18.8 Editorial 889 McP 16/8/05 2:57 PM Page 890
EDITORIALS NATURE|Vol 436|18 August 2005
thresholds — and has come up with the ‘h-index’. This is the highest prohibited assessment panels from judging papers by the impact
number of papers that a scientist has written that have each received factors of the journals in which they appeared. What the costs of that
at least that number of citations; an h-index of 50, for example, will be in panel members’ time remains to be seen.
means someone has written 50 papers that have each had at least 50 The common approach of the RAE’s disciplinary panels is to
citations. The citations are counted using the tables of citations-to- assess up to four submitted outputs (typically research papers or
date provided by Thomson ISI of Philadelphia. Within a discipline, patents) per researcher, of which a proportion will be assessed in
the approach generates a scale of comparison that does seem to some detail (25% for the biol-
“Given the potential
reflect an individual’s achievement thus far, and has already attracted ogists, 50% for the physicists).
favourable comment (see page 900). The top ten physicists on this There will no doubt be some- for such indicators to
scale have h values exceeding 70, and the top ten biologists have thing of a challenge in taking be seized upon by
h values of 120 or more, the difference reflecting the citation char- into account the fact that a
administrators, readers
acteristics of the two fields. typical publication has several
should examine the
The author placed his proposal on a preprint server last week co-authors.
suggestion and provide
(www.arxiv.org/abs/physics/0508025), thereby inviting comment These outputs will sit along-
before publication. Given the potential for indicators to be seized side indicators of the research the author with some
upon by administrators, readers should examine the suggestion and environment such as funds and peer assessment.”
provide the author with peer assessment. infrastructure, and of esteem,
Whatever its virtues, any citation analysis raises as many questions such as personal awards and prestige lectures. The specific indi-
as it answers and also tracks just one dimension of scientific outputs. cators to be considered and the weightings applied are now open
Naturehas consistently advocated caution in the deployment of the for public consultation (see www.rae.ac.uk/pubs/2005/04/docs/
impact factor in particular as a criterion of achievement (an index consult.doc). Given that the RAE is so influential both nationally
that Hirsch’s h indicator happily ignores).Wisely, the UK Research and,as a technique, internationally, there is a lot at stake. Stake-
Assessment Exercise (RAE) has long committed itself to a broader holders should express any concerns they may have by the deadline
view and the organizers of the next RAE, to take place in 2008, have of 19 September. ■
Climate for progress since the programme issued a strategic plan just two years ago, some
of the completion dates for the 21 reports that it plans to produce
have slipped by several years.
The painstaking US approach to the assessment of US government officials say that they were too ambitious in
climate-change science yields some useful results. setting the original deadlines. But they also admit that some of
the panels’ work is being delayed by two other factors: the need to
T
he US Climate Change Science Program, which is seeking to comply with recent legislation that makes it extremely difficult
produce a comprehensive set of reports on climate change, has to incorporate fresh scientific
“The handling of the lower-
been widely criticized as a stalling exercise whose work dupli- information into government
cates that of the Intergovernmental Panel on Climate Change, and reports, and the requirement atmosphere report over
whose findings may be prone to political manipulation. that the climate-change work the next few months will
However, the programme yielded some promising outcomes last is approved at the political, as help to clarify whether the
week,when several participants of a panel it convened published well as the scientific, level.
programme really is a
some findings on the apparent discrepancy between the record of The programme’s director,
serious attempt to grapple
warming on the Earth’s surface and the change experienced in the James Mahoney, argues that the
troposphere, the lowest level of the atmosphere (see page 896). latter process will be managed with uncertainty in
The climate-change programme had brought together 22 experts in a way that will preclude polit- climate-change science.”
to look into the problem. In the course of five meetings and count- ical interference. Once the sci-
less e-mail exchanges, the participants conceded flaws in some of the entific authors have agreed their final draft, the report will be posted
their earlier analyses and produced new data sets, some of which online for a 45-day period of public comment. Once that closes,
were published online in Science (doi:10.1126./science1114772; the report will be revised again. Only then, in the final step before
doi:10.1126./science1114867; doi:10.1126./science1115640; 2005). publication, will it be reviewed by administration officials.
The release of the draft report summarizing the panel’s conclu- This process will make it hard for the Bush administration to put
sions for public review, which was due in June, is being delayed, its own spin on the report’s scientific findings — provided that the
however. The delay may reflect the intrinsic difficulty of getting a drafts are published promptly, without political interference, and that
large committee containing disparate views to agree on a final form the final documents adhere to the spirit of the drafts. The handling
of wording. But it seems to fit in with a pattern at the climate-change of the lower-atmosphere report — the first from the programme’s
programme, which was criticized by the Government Accountabil- strategic plan — in the next few months will help clarify whether
ity Office in April for failing to meet a 2004 deadline for issuing a the programme is a serious attempt to grapple with uncertainty in
new national climate-change assessment. Critics also point out that climate-change science, or is merely an exercise in obfuscation. ■
890
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18.8 Res Highlights 892-893 McP 12/8/05 5:43 PM Page 892
Vol 436|18 August 2005
RESEARCH HIGHLIGHTS
R
Getting good cleavage VIE
Curr. Biol.15,1401–1406 and 1407–1412 (2005) RILL/ELSE
The composition of the cell membrane and G/J. B
signalling via calcium ions are key to ON
W
controlling the final step of cell division, R.
according to two independent studies.
Julie Brill and her colleagues at the Hospital
for Sick Children in Toronto, Canada, found an
important component of the calcium
signalling pathway, the phosphoinositide PIP2,
in the dividing cell’s membrane. Sperm cells
from the fruitfly Drosophiladeprived of either
calcium or PIP2 (pictured bottom right,
compared with control, top right) can begin
cytokinesis, but not complete it, the
researchers found.
Meanwhile, a group of researchers led by
Seth Field of Harvard Medical School in
Boston has shown that PIP2 accumulates at
the cleavage furrow in mammalian cells,
where the molecule helps the cell membrane
to stick to the contracting ring of proteins that
divides the cell.
BIOTECHNOLOGY interfering RNAs with a modified form of METABOLISM
Made to order the natural protein collagen. Melting fat
The group used such a mixture, injected
Nature Biotechnol.doi:10.1038/nbt1128 (2005) into mice’s bloodstreams, to shut down the Dev. Cell9,271–281 (2005)
Escherichia colibacteria have been genes implicated in the spread of prostate The insulin signalling pathway controls
engineered to make novel polyketides — cancer to bone. This inhibited the cancer’s whether the body burns or stores fat. Stephen
molecules that can kill bacteria and inhibit spread, without the side-effects or Cohen’s group at the European Molecular
cancer cells — using a modular approach. inflammation that have plagued other Biology Laboratory in Heidelberg, Germany,
Typically, soil microorganisms make approaches — providing the first hints have now found that a protein called Melted
polyketides using hefty enzymes encoded in that small RNAs could treat advanced is involved in regulating this pathway
genetic sequences up to 50,000 bases long. To prostate cancer. The researchers found that Melted, which
make these genes more wieldy, researchers resides in the cell membrane, binds to
headed by Daniel Santi from Kosan COMPUTER SIMULATION proteins from two different branches of the
Biosciences in Hayward, California, divided Cracked it insulin pathway. Mutating the gene for
the sequences into modules about 5,000 base Melted in the fruitfly Drosophilareduced the
pairs long. They then engineered modules Phys. Rev. Lett.95,060202 (2005) activity of the TOR pathway but activated
from different enzymes to combine inside Warming news for materials scientists: FOXO, producing flies with 40% less body fat
E. coli, allowing the bacterium to synthesize a way to simulate the behaviour of solids than normal. Giving the mutants the human
polyketides not found naturally. Such that previously worked only when the version of the gene restored their fat,
compounds could help fight drug-resistant temperature of the material was set to suggesting that Melted is involved in human
pathogens. absolute zero has been adapted to work at fat metabolism, too.
higher, more realistic temperatures.
PROSTATE CANCER Laurent Dupuy of the Lawrence ELECTRONICS
RNA interference delivers Livermore National Laboratory in California Y NOT?
and his colleagues have made this
Proc. Natl Acad. Sci. USAdoi:10.1073/pnas.0501753102 improvement to the quasicontinuum Nature Mater.
(2005) method, which combines atomic-scale doi:10.1038/nmat1450 (2005)
Small interfering RNA molecules have been simulations of crucial regions with cruder The first electrical switch
shown to shut down disease-causing genes in treatment of the rest. This technique speeds made entirely from carbon
many animal models, but an obstacle has the simulation of phenomena such as nanotubes has been
been delivering the RNA to where it is fracture, which involve processes at scales unveiled by Prabhakar
needed. Takahiro Ochiya at the National from the atomic to the macroscopic. The Bandaru of the University
Cancer Center Research Institute in Tokyo team showcases its work by simulating the of California, San Diego,
and his colleagues have pioneered one formation of dislocations in a flat nickel and his colleagues. They
possible solution by combining small crystal at different temperatures. report that a current
892
© 2005 Nature PublishingGroup
©©22000055 NNaattuurree PPuubblliisshhiinngg GGrroouupp
18.8 Res Highlights 892-893 McP 12/8/05 5:44 PM Page 893
Vol 436|18 August 2005 RESEARCH HIGHLIGHTS
JOURNAL CLUB
flowing across two branches of a Y-shaped their quantum glove are unknown, so they
nanotube can be switched on and off by only carry information about handedness. Douglas Hamilton
applying a voltage to the third branch. University of Maryland
Although the details of the switching process CELL BIOLOGY
Now you see them, now you
are not yet well understood, it should be Nuclear escape
don’t, but at least this
possible to use the Y-shaped nanotube to
researcher knows why his
create a NOT gate, which inverts its input, Cell122,379–391 (2005)
favourite features of Saturn’s
and to implement other logic operations. The editing of messenger RNA, or splicing,
rings have gone missing.
was assumed to occur only in a cell’s nucleus.
ANTIBIOTIC RESISTANCE But now splicing has been seen in human Images from the Voyager
TB’s second secret platelets, which have no nucleus. spacecraft in the 1980s revealed
Mature mRNA molecules, which are used dark streaks across Saturn’s rings,
Proc. Natl Acad. Sci. USA to synthesize proteins, are made by splicing of dubbed spokes. They grew rapidly
doi:10.1073_pnas.0505446102 (2005) pre-mRNA. Andrew Weyrich’s group at the to span thousands of kilometres,
One reason for the spread of tuberculosis is University of Utah in Salt Lake City identified sheared apart, and then faded over
the remarkable ability of its causative agent, components of the splicing apparatus in a few hours.
Mycobacterium tuberculosis, to resist platelets (pictured below, surrounded by red These unusual structures are
antibiotics. This stems, in part, from the blood cells), and showed that external signals known to be composed of
low permeability of the cell envelope, a micrometre-sized dust grains,
mNoewm ba rgaennee i tnhsaidt ec othoerd oirngaatnesis am s’es ccoenlld w lainlle. of ARF/SPL mlaragdee r binyg m peatretiocrloesid, bimutp tahcetisr on
H
defence within the cell’s cytoplasm has been D. SC evolution is not well understood. I
discovered. had been working on this problem,
Charles Thompson from the University of and had come up with some very
British Columbia in Vancouver and his team promising leads, based on models
spotted that a mutation in the gene whiB7 of the motions of charged dust
made the bacterium Streptomyces lividans grains. However, the late 1990s
more vulnerable to antibiotics. brought data that threatened to
Mycobacteriumalso carries this gene, make my theory redundant.
and mutating it had the same effect. The Colleen McGhee from Wellesley
researchers analysed gene activity to College in Massachusetts and her
study the protection mechanism. colleagues were using the Hubble
Space Telescope to monitor
QUANTUM PHYSICS Saturn's rings. They found,
It must be glove mysteriously, that spokes lessened
could set the machinery going. This in number and intensity over
Phys. Rev. A72,022304 (2005). prompted them to examine bone-marrow several years, then disappeared
Information about handedness can be cells called megakaryocytes, which spawn altogether in late 1998. I learnt
transmitted by a physical object such as a platelets. Parts of the splicing complex were about these observations at
glove, because the left hand is different from also found in these cells’ cytoplasm. meetings, and was left wondering
the right. But what would a pair of ‘quantum what had happened to the spokes.
gloves’ look like? GENETICS McGhee et al.now offer an
Daniel Collins, formerly of the University Surprise connection elegant explanation for the spokes’
of Geneva, Switzerland, and his colleagues remarkable disappearing act
point out that four entangled particles can Mol. Cell19,381–391 (2005) (Icarus173,508–521; 2005). They
assume one of two configurations that Inside the cell nucleus, DNA wraps around suggest the spokes form a dusty
are, like gloves, mirror images proteins called histones. Chemical scattering layer above the thin
of each other. modifications of these proteins are thought GES main rings. Until the mid-1990s,
A
M
But these gloves to switch genes on and off. A study of the Y I Saturn’s rings were seen edge-on,
T
are much more histone H3 provides clues to how T so sunlight had to travel a long
GE
economical than a sophisticated this control may be. Y/ distance through the dusty layer
classical glove, they Adding methyl groups to the ninth amino RSLE before reflecting from the rings,
argue, because they are acid in this protein’s chain had been thought NDE making the spokes look dark.
KI
burdened with less of the to deactivate genes. Gerd Blobel of the G Now, Saturn’s rings are tilted
N
extra information that Children’s Hospital of Philadelphia and his RLI towards the Sun. This geometry
O
comes from knowing the colleagues were therefore surprised to find D makes the spokes invisible to
position of every part di- and tri-methylation of this region in Earth-based telescopes, and even
of a classical glove with active genes. These modifications disappear to the Cassini spacecraft currently
certainty. when the gene is repressed. Other histone orbiting Saturn. But the dusty
In contrast, the absolute modifications must also be influencing the spokes still exist, and so my
positions of the particles in gene’s status. budding theory survives.
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18.8 News 894-895 McP 16/8/05 2:40 PM Page 894
Vol 436|18 August 2005
NEWS
Synthetic biologists face
up to security issues
WASHINGTON DC bacteria (H. O. Smith et al. Proc. Natl Acad. Sci.
Concerns about safety and security in the USA100,15440–15445; 2003).
young field of synthetic biology are developing Others are using made-to-order compo-
almost as rapidly as the research itself. nents to re-engineer the genomes of bacteria
With scientists now able to create complete or viruses — either to investigate how they
genomes from scratch and to introduce new work or to try to give them abilities that they
characteristics into viruses and bacteria, there would not have naturally, such as producing
are fears that accidental — or worse, inten- drug molecules or generating hydrogen for use
tional — release of such creatures could occur. as an energy source. In theory, these tech-
As a result, the US government, academics niques could be used to create deadly organ-
and the field’s first private companies are now isms in the lab, such as Ebola or anthrax, or to
working together to address the potential make bacteria more dangerous by giving them
problems before they become a reality. antibiotic resistance, for example, or the abil-
Synthetic biology is one of the priorities for ity to make additional toxins.
the newly formed US National Science Advi- Does this increased sophistication mean
sory Board for Biosecurity (NSABB), which that the field needs radically new rules? Drew
met for the first time in June. A working group Endy, a synthetic biologist at Massachusetts
on the topic, set up by the board, will begin its Institute of Technology and one of the leaders
discussions later this month. Its members have of the Sloan Foundation project, is not sure.
already consulted synthetic biologists who have “There hasn’t been a clear conversation about
set up their own governance project, funded by whether de novosynthesis poses a different
the Alfred P. Sloan Foundation in New York, threat from genetic engineering,” he says.
which will have its first meeting in September. Wendell Lim at the University of California,
And one of the first public discussions of the San Francisco, who uses synthetic biology to
issue comes this week, at a synthetic-biology study basic processes such as how cells grow
meeting in San Francisco on 19–20 August. As and move, says that there is nothing special
well as looking at the field’s potential in areas about the field that requires blanket restric- The ability to build genomes in the lab has raised
such as drug development, cellular repro- tions and that each type of study should be fears that the technology could be abused.
gramming and biological robotics, partici- judged on its own risks and merits. “To
pants will tackle ethical and legal issues. broadly raise alarms about all such approaches should screen certain raw materials that scien-
The discussion will echo an event in 1975, is akin to saying we should worry about all tists could use to brew up their own DNA.
when pioneers of genetic engineering retreated uses of semiconductors because one of their “Basically you want a series of licences to cover
to the Asilomar Conference Center in Califor- uses could be in launch systems for nuclear almost every step where there’s a reasonable
nia to set safety and ethical principles to guide weapons,” he says. “We need to distinguish the bottleneck you can regulate,” he says.
their field. The fear was that modified microor- sub-areas of the field and specific biological But many argue that the openness of the field
ganisms might escape into the environment components that truly pose a hazard, and fig- offers a built-in safety mechanism against unin-
with unpredictable effects, perhaps causing ure out how to regulate them.” tentionally creating something harmful. For
disease or out-competing wild strains. instance, Endy’s lab hosts an online library of
Now synthetic biologists have much more Taking care parts that can be built into genomes. The library
powerful techniques at their disposal. But there are some general precautions that is open source, meaning that all scientists in the
Improved DNA synthesis means, for example, most synthetic biologists support. Many think field can test them. “There’s an element of safety
that microbial genomes can be built from it would make sense to monitor products in using well characterized components,” says
scratch, bypassing the need to get hold of the ordered from companies that generate syn- Christopher Voigt, a synthetic biologist at the
actual organism.A dramatic demonstration of thetic genes on demand, such as Codon University of California, San Francisco.
the potential consequences came in July 2002, Devices in Cambridge, Massachusetts, and Blue Other synthetic biologists point out the suc-
when researchers at the University of New Heron Biotechnology in Bothell, Washington. cess of initiatives to encourage young scientists
York at Stony Brook reported that they had George Church, who co-founded Codon to think about safety and ethical issues relating
synthesized an infectious poliovirus using Devices this spring, wants to go further, argu- to their work. “It’s important to talk about ways
mail-order DNA (see Nature418,265; 2005). ing that strict regulation is a key to heading off to minimize risk, and one of the most impor-
Genome sequencer Craig Venter followed that the public-relations problems that have tant ways to do that is to train responsible
by announcing plans to build a bacterium plagued other areas of biotechnology. As well scientists and engineers,” says Christina
from lab synthesized DNA and by taking just as monitoring orders for components such as Smolke, a chemical engineer at the California
three weeks to synthesize a virus that infects synthetic genes, he says the government Institute of Technology in Pasadena.
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NATURE|Vol 436|18 August 2005 NEWS
MARS SOCIETY
Follow the action from
the meeting of Mars
enthusiasts in Boulder,
Colorado.
www.nature.com/news
N/SPL NASA draws up blueprint for
DE
G
O
S. craft to reach Moon and Mars
BOULDER, COLORADO a large Apollo-like capsule or a smaller,
NASA last week revealed its plans for slimmer shuttle. NASA will pick the
the next generation of space vehicles, winning design in 2006.
designed to get humans back to the Moon Mars Society members were thrilled to
and, eventually, to Mars. hear about the vehicle plans and they
On 13 August, Christopher Shank, support Griffin in getting started. But they
special assistant to NASA administrator object to the proposed timeline, and the
Michael Griffin, described the agency’s size of the CEV. They want to see a 7-tonne
future exploration machinery, which is vehicle being used as this could take
proposed to replace the shuttle in 2010. humans directly to the Moon and back,
His talk, given at the Mars Society and so accelerate lunar-base construction.
Conference in Boulder, Colorado, precedes NASA’s 25-tonne CEV could carry six
a full report scheduled for release this people as well as ISS supplies and parts.
month, called the Exploration Systems But to reach the Moon it would need to
Architecture Study. This will rendezvous with another, as
lay out how NASA intends to “It will be a ‘go as yet undeveloped, vehicle in
meet President George W. you can afford to pay’ lunar orbit before returning
Bush’s goal of sending to Earth.
approach. Let the
humans back to the Moon “It’s a choice between
by 2020 in preparation for long, hard slog begin.” having a Cadillac ISS
a Mars mission. programme or a lunar
“It will be a ‘go as you can afford to pay’ base,” says Robert Zubrin, society
approach,” Shank told the 300 members of president. He argues that continuing to
the Mars Society, a private group whose focus on the ISS does little to further the
mission is to promote human exploration goal of getting to Mars. Shank counters
and colonization of the red planet. “Let that NASA does not separate the ISS from
the long, hard slog begin.” Moon and Mars missions, as the same
So far, observers are giving synthetic biolo- That, he said, means deferring other components are integral to both.
gists credit for tackling such issues. But some, programmes, such as future research on Zubrin and his fellow enthusiasts
such as Paul Rabinow, an anthropologist at the the International Space Station (ISS) and applauded the plans for an HLV, which is
University of California, Berkeley, think that lunar-base development, until the new critical for a martian journey. But some,
the field needs to take a broader view than it space vehicles come online. The first such as David Schuman, a lawyer at
has so far. He is speaking at the San Francisco vehicle will be a 25-tonne Crew NASA’s Goddard Space Flight Center in
meeting this week and says he will tell atten- Exploration Vehicle (CEV), which will Greenbelt, Maryland, criticized the
dees to pay more attention to the danger that ride into space on a modified shuttle decision to delay HLV development until
synthetic biology could be abused for biowar- booster rocket; this will initially supply after 2010.
fare or bioterrorism, something that is harder and return ISS crews. After 2010, work Without solutions to the shuttle’s
to control than the risk of accidents. will begin on a 100-tonne Heavy Lift current safety issues, he notes, “we could
“The field has been attempting to turn this Vehicle (HLV) that can carry heavier be left without any heavy-lift capability”.
into a safety issue, but we’re living today in a payloads. The HLV will also use a rocket That would delay ISS completion, pushing
security regime,” he told Nature. “Dealing with modified from the shuttle’s boosters and Moon and Mars timelines back another
safety is good, but they’re fooling themselves if external fuel tank. decade. As it is 36 years since the first lunar
they think that’s going to be the end of this Lockheed Martin and a team at landing, Zubrin and fellow exploration
question.” Northrop Grumman–Boeing have proponents say that delay is not only
Venter agrees, arguing that rather than reg- contracts to develop the three- to six- unbelievable — it is unacceptable. ■
ulating labs and companies, governments person CEVs. Potential designs include Kendall Powell
need to use synthetic biology to develop ways
to defeat bioterrorist attacks, such as produc-
ing drugs and vaccines, or sensors to detect
altered organisms in the environment. “If we’re N
TI
not concentrating 100% of our defensive effort One of the AR
M
on countermeasures, I think we’re missing the designs for the D
big picture,” he told the NSABB in June. ■ Crew Exploration Vehicle, HEE
K
C
Erika Check which would service the space station. O
L
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