WWW.NATURE.COM/NATURE
This press release is copyright Nature.
VOL.468 NO.7326 DATED 16 DECEMBER 2010
This press release contains:
· Summaries of newsworthy papers:
Comment: Cross-breeding could drive Arctic species extinct
Genetics: A bumper crop of enhancers
Biochemistry: How to make Taxol
Cancer: A variegated picture of leukaemia
Materials science: Atom-by-atom spectroscopy
And finally… Crystals with pleats
· Mention of papers to be published at the same time with the same embargo
· PRESS BRIEFING:Ecology: Not too late to save the polar bear
· Geographical listing of authors
Editorial contacts: While the best contacts for stories will always be the authors themselves, in some cases the Nature editor who handled the paper will be available for comment if an author is unobtainable. Editors are contactable via Ruth Francis on +44 20 7843 4562. Feel free to get in touch with Nature's press contacts in London, Washington and Tokyo (as listed at the end of this release) with any general editorial inquiry.
Warning: This document, and the Nature papers to which it refers, may contain information that is price sensitive (as legally defined, for example, in the UK Criminal Justice Act 1993 Part V) with respect to publicly quoted companies. Anyone dealing in securities using information contained in this document or in advanced copies of
Nature’s content may be guilty of insider trading under the US Securities Exchange Act of 1934.
The Nature journals press site is at http://press.nature.com
· PDFs for the Articles, Letters, Progress articles, Review articles, Insights and Brief Communications in this issue will be available on the Nature journals press site from 1400 London time / 0900 US Eastern Time on the Friday before publication.
· PDFs of News & Views, News Features, Correspondence and Commentaries will be available from 1400 London time / 0900 US Eastern Time on the Monday before publication.
PICTURES: While we are happy for images from Nature to be reproduced for the purposes of contemporaneous news reporting, you must also seek permission from the copyright holder (if named) or author of the research paper in question (if not).
HYPE: We take great care not to hype the papers mentioned on our press releases, but are sometimes accused of doing so. If you ever consider that a story has been hyped, please do not hesitate to contact us at [email protected], citing the specific example.
PLEASE CITE NATURE AND OUR WEBSITE www.nature.com/nature AS THE SOURCE OF THE FOLLOWING ITEMS. IF PUBLISHING ONLINE, PLEASE CARRY A HYPERLINK TO http://www.nature.com
Comment: Cross-breeding could drive Arctic species extinct (p. 891)
Loss of sea ice around the North Pole is encouraging the formation of hybrids that could push many species to extinction, say Brendan Kelly, Andrew Whiteley and David Tallmon in a Comment in Nature this week. They identify at least 22 marine mammal species at risk of hybridization, 14 of which are listed — or are candidates for listing — as endangered, threatened or of special concern by one or more nations. The authors call for a monitoring programme to see how much cross-breeding is going on, so that the International Union for the Conservation of Nature can develop better protection plans.
Many Arctic hybrids have already been spotted. In 2006, Arctic hunters shot a polar bear–grizzly bear mix — a white bear with brown patches — which the media quickly dubbed a ‘pizzly’. In the late 1980s, a whale skull thought to be that of a narwhal–beluga mix was found in west Greenland; in 2009, an apparent bowhead–right-whale hybrid was photographed in the Bering Sea. Porpoises and seals are known to be
hybridizing. In 2010, another polar–grizzly hybrid was killed.
The Arctic Ocean is predicted to be ice free in summer before the end of the century. Polar bears will spend even more time in grizzly bear stomping grounds. Seals and whales currently living in different oceans, separated by ice, will soon share the same northern waters. Isolated populations will come into contact and mate, and some — such as the North Pacific right whale — could be driven to extinction. “The rapid
disappearance of sea ice leaves little time to lose,” the authors write.
CONTACT
Brendan Kelly (National Marine Mammal Laboratory, National Oceanic and Atmospheric Administration, Juneau, AK, USA)
Tel: +1 907 209 6531; E-mail: [email protected]
[1] Genetics: A bumper crop of enhancers (AOP)
DOI: 10.1038/nature09692
This paper will be published electronically on Nature's website on 15 December at 1800 London time / 1300 US Eastern Time as part of our AOP (ahead of print) programme. Although we have included it on this release to avoid multiple mailings it will not appear in print on 16 December, but at a later date.
More than 2,000 putative regulatory sequences, examples of which are enhancers — regions of the genome that bind regulatory proteins to enhance gene activity during development — have been identified in human embryonic stem cells (hESCs), a Nature study reports. The finding boosts our understanding of the regulatory mechanisms that control gene expression during early embryonic development.
Joanna Wysocka and colleagues identified unique modifications to the chromatin that seems to bookmark these early developmental enhancers. The 2,000 or so potential enhancers described are either active in hESCs or associated with early developmental genes.
Regulatory DNA elements, such as enhancers, are important in the control of cell fate and development but have been challenging to identify. And it is thought the wealth of regulatory sequences identified here could help track and isolate transient, rare cell
populations during early stages of human embryonic development.
CONTACT
Joanna Wysocka (Stanford University, CA, USA)
Tel: +1 650 736 0672; E-mail: [email protected]
[2] Biochemistry: How to make Taxol (AOP)
DOI: 10.1038/nature09628
This paper will be published electronically on Nature's website on 15 December at 1800 London time / 1300 US Eastern Time as part of our AOP (ahead of print) programme. Although we have included it on this release to avoid multiple mailings it will not appear in print on 16 December, but at a later date.
The first X-ray crystal structure of a diterpene cyclase provides an important piece of evolutionary history for the biosynthetic enzymes that help make many complex natural products.
Terpenoids, a diverse class of small organic molecules, provide the tastes, odours and biological activities of many culinary and medical plant extracts. Simple linear terpenes are frequently cyclized and chemically modified to make other biologically active compounds, including menthol, vitamin A and all steroids. Although the X-ray crystal structures of several enzymes responsible for making these compounds are known, the three-dimensional structure of a diterpene cyclase was not known. In this week’s Nature, David Christianson and colleagues reveal the structure of taxadiene synthase, the enzyme that catalyzes the formation of the core molecular scaffold of the anticancer
drug Taxol.
The authors were surprised to see that one part of the protein resembles a class I terpenoid cyclase fold and another part resembles a class II terpenoid cyclase fold, indicating that this enzyme may represent an evolutionary link between these two distinct enzyme families.
CONTACT
David Christianson (University of Pennsylvania, Philadelphia, PA, USA)
Tel: +1 215 898 5714; E-mail: [email protected]
[3] Cancer: A variegated picture of leukaemia (AOP)
DOI: 10.1038/nature09650
This paper will be published electronically on Nature's website on 15 December at 1800 London time / 1300 US Eastern Time as part of our AOP (ahead of print) programme. Although we have included it on this release to avoid multiple mailings it will not appear in print on 16 December, but at a later date.
Leukaemia-propagating cells and the cells derived from them are genetically heterogeneous, indicates a Nature study that has implications for targeted cancer therapy.
Analysing single cells from human B-cell acute lymphoblastic leukaemias (ALL), Mel Greaves and colleagues mapped the genetic heterogeneity of cells within a given tumour sample, the evolutionary path by which different subclones emerged and the ongoing dynamic changes associated with relapse. Subclones are genetically heterogenous and have complex evolutionary histories. The authors show that genetic changes within subclones are dynamic and change in the lead up to a diagnosis and in relapse.
The study also offers a plausible explanation for why advanced cancer is so difficult to treat, when the very cell that triggers the disease is itself genetically diverse and a moving target.
CONTACT
Mel Greaves (The Institute of Cancer Research, Sutton, UK)
Tel: +44 20 8722 4073; E-mail: [email protected]
[4] Materials science: Atom-by-atom spectroscopy (AOP)
DOI: 10.1038/nature09664
This paper will be published electronically on Nature's website on 15 December at 1800 London time / 1300 US Eastern Time as part of our AOP (ahead of print) programme. Although we have included it on this release to avoid multiple mailings it will not appear in print on 16 December, but at a later date.
Electronic spectra obtained from individual carbon atoms in a graphene sheet are presented online in Nature this week. Using an electron microscope with atomic resolution and low beam energy, Kazu Suenaga and Masanori Koshino distinguish atoms in different coordination states — opening the way to exploring the local electronic structures of other materials.
Recent advances in electron microscopy have made it possible to image and identify atoms of different elements in complex materials. The related goal of probing the electronic structure of individual atoms — especially light atoms, such as carbon — has been hampered by a combination of extremely weak signals and specimen damage caused by the electron beam. Suenaga and Koshino have overcome these difficulties, using a low-voltage electron microscope to collect electron energy-loss spectra from single atoms.
The authors investigated the electronic structure of carbon atoms at and near the edge of a single atomic layer of graphene. This material is a promising candidate for nanometre-scale devices, with electronic properties largely governed by structures at the edges of a sheet. By comparing the single-atom spectra they collected to theoretical calculations, the authors were able to discriminate among carbon atoms with one, two or three bonds to other atoms — illustrating the potential for applying the technique to individual molecules.
CONTACT
Kazu Suenaga (National Institute of Advanced Industrial Science and Technology, Higashi, Japan)
Tel: +81 298 61 6850; E-mail: [email protected]
[5] And finally… Crystals with pleats (pp 947-951; N&V)
A design feature well known in skirts and trousers has now been identified in curved two-dimensional crystals. As reported in this week’s Nature, crystalline arrays grown on a negatively curved surface can develop linear defects analogous to fabric pleats. The results will facilitate a more general exploration of defects in curved spaces, including potential applications in engineered materials.
The problem of tiling a curved surface with hexagons is familiar from soccer balls and geodesic domes, where pentagons are added to accommodate the spherical (positive) curvature. Interacting particles that form hexagonal patterns on a plane — known as ‘colloidal crystals’ — adopt these and other types of topological defect when grown on a sphere.
William Irvine and colleagues have developed an experimental system that allows them to investigate crystal order on surfaces with spatially varying curvature, both positive and negative. On negatively curved surfaces, they observe two types of defect that haven’t been seen before: isolated heptagons (analogous to the pentagons on a sphere), and pleats. The pleats allow a finer control of crystal order with curvature than is possible with isolated point defects, and may find application in curved structures such as waisted nanotubes, or in materials created by soft lithography or directed self-assembly.
CONTACT
William Irvine (University of Chicago, IL, USA)
Tel: +1 773 702 7197; E-mail: [email protected]
Francesco Stellacci (École Polytechnique Fédérale de Lausanne, Switzerland) N&V author
Tel: +41 21 6937872; E-mail: [email protected]
ALSO IN THIS ISSUE…
[6] Emerging properties of animal gene regulatory networks (pp 911-920)
[7] TRIM24 links a non-canonical histone signature to breast cancer (pp 927-932)
[8] CRTC3 links catecholamine signalling to energy balance (pp 933-939)
[9] Tidal dissipation and the strength of the Earth’s internal magnetic field (pp 952-954)
[10] Intercalation of a newtier of transcription regulation into an ancient circuit (pp 959-963)
ADVANCE ONLINE PUBLICATION
This paper will be published electronically on Nature's website on 15 December at 1800 London time / 1300 US Eastern Time as part of our AOP (ahead of print) programme. Although we have included it on this release to avoid multiple mailings it will not appear in print on 16 December, but at a later date.
[11] H2AX prevents CtIP-mediated DNA end resection and aberrant repair in G1-phase lymphocytes
DOI: 10.1038/nature09585
[12] ATM damage response and XLF repair factor are functionally redundant in joining DNA breaks
DOI: 10.1038/nature09604
PRESS BRIEFING:
Ecology: Not too late to save the polar bear (pp 955-958; N&V)
Previously predicted declines in polar bear (Ursus maritimus) numbers are not necessarily a foregone conclusion, indicates a modelling study in this week’s Nature, which projects that curbing greenhouse gas emissions could have positive effects for the animals.
The dramatic loss of Arctic sea ice with climate change has led to the prediction of a tipping point beyond which ice loss is irreversible and polar bear habitat will be catastrophically lost. But this study, by Steven Amstrup and colleagues, concludes that there is no tipping point.
The linear relationship between temperature and sea-ice coverage indicates that reducing greenhouse gas emissions could help reduce projected declines in polar bear habitat, helping the animals persist throughout the century in more areas and greater numbers.
Polar bears are viewed by many as sentinels of the Arctic ecosystem, with trends in their sea-ice habitats foreshadowing future global changes. Strategies aiming to reduce greenhouse gas emissions for the benefit of polar bears should therefore yield conservation benefits throughout and beyond the Arctic.
CONTACT
Steven Amstrup (US Geological Survey, Anchorage, AK, USA)
Tel: +1 406 581 6183; E-mail: [email protected]
Andrew Derocher (University of Alberta, Canada) N&V author
Tel: +1 780 492 5570; E-mail: [email protected]
GEOGRAPHICAL LISTING OF AUTHORS…
The following list of places refers to the whereabouts of authors on the papers numbered in this release. For example, London: 4 - this means that on paper number four, there will be at least one author affiliated to an institute or company in London. The listing may be for an author's main affiliation, or for a place where they are working temporarily. Please see the PDF of the paper for full details.
GERMANY
Berlin: 7
Göttingen: 7
JAPAN
Tsukuba: 4
NETHERLANDS
Leiden: 5
TAIWAN
Taichung: 7
UNITED KINGDOM
London: 3
Newcastle upon Tyne: 3
Oxford: 3
Sutton: 3
UNITED STATES OF AMERICA
California
Berkeley: 9
La Jolla: 8
Los Angeles: 8
Pasadena: 6
San Francisco: 10
South San Francisco: 10
Stanford: 1, 7
Colorado
Boulder: 2
Illinois
Chicago: 5
Urbana: 2
Massachusetts
Boston: 12
Missouri
St Louis: 11
New York
New York: 5, 7, 12
Ohio
Cincinnati: 7
Pennsylvania
Philadelphia: 2
Tennessee
Memphis: 11
Texas
Houston: 7, 8
Washington
Pullman: 2
PRESS CONTACTS…
From North America and Canada
Neda Afsarmanesh, Nature New York
Tel: +1 212 726 9231; E-mail: [email protected]
From Japan, Korea, China, Singapore and Taiwan
Mika Nakano, Nature Tokyo
Tel: +81 3 3267 8751; E-mail: [email protected]
From the UK
Rebecca Walton, Nature, London
Tel: +44 20 7843 4502; E-mail: [email protected]
About Nature Publishing Group (NPG):
Nature Publishing Group (NPG) is a publisher of high impact scientific and medical information in print and online. NPG publishes journals, online databases and services across the life, physical, chemical and applied sciences and clinical medicine.
Focusing on the needs of scientists, Nature (founded in 1869) is the leading weekly, international scientific journal. In addition, for this audience, NPG publishes a range of Nature research journals and Nature Reviews journals, plus a range of prestigious academic journals including society-owned publications. Online, nature.com provides over 5 million visitors per month with access to NPG publications and online databases and services, including Nature News and NatureJobs plus access to Nature Network and Nature Education’s Scitable.com.
Scientific American is at the heart of NPG’s newly-formed consumer media division, meeting the needs of the general public. Founded in 1845, Scientific American is the oldest continuously published magazine in the US and the leading authoritative publication for science in the general media. Together with scientificamerican.com and 15 local language editions around the world it reaches over 3 million consumers and scientists. Other titles include Scientific American Mind and Spektrum der Wissenschaft in Germany.
Throughout all its businesses NPG is dedicated to serving the scientific and medical communities and the wider scientifically interested general public. Part of Macmillan Publishers Limited, NPG is a global company with principal offices in London, New York and Tokyo, and offices in cities worldwide including Boston, Buenos Aires, Delhi, Hong Kong, Madrid, Barcelona, Munich, Heidelberg, Basingstoke, Melbourne, Paris, San Francisco, Seoul and Washington DC. For more information, please go to www.nature.com.
