Volume 459 Issue 7248, 11 June 2009

On the cover, a composite of 25 images showing the east limb of the Sun during the total solar eclipse of 1 August 2008, observed from Mongolia. The latest methods of image processing were used to bring out spatial details, revealing the structure of the coronal magnetic field. As Jay Pasachoff explains in a Review, a new generation of eclipse studies is linking solar observations from satellites with ground-based observations. Credit: Miloslav Druckmüller (Brno University of Technology)/Martin Dietzel & Peter Aniol (ASTELCO Systems, GmbH)/Vojtech Rušin (Slovak Academy of Sciences).

Authors

Editorials

  • Editorial |

    English libel law adversely affects every publisher and website host whose content can be read in the United Kingdom. It must be changed.

  • Editorial |

    The H1N1 flu epidemic is not the world's only disease threat.

  • Editorial |

    Journals and funders must insist that genetically modified mouse strains are fully available.

Research Highlights

Journal Club

News

News in Brief

Features

  • News Feature |

    Assessing the effects of television on young children is far from easy. But, as researchers tell Jim Schnabel, that is no reason not to try.

    • Jim Schnabel
  • News Feature |

    The boundaries of biology reach farther below Earth's surface than scientists had thought possible. Amanda Leigh Mascarelli delves into how microbes survive deep underground.

    • Amanda Leigh Mascarelli

Correspondence

Essay

  • Essay |

    As letters and diaries give way to e-mails and laptops, fresh challenges and opportunities have emerged for archivists. Jeremy Leighton John explores the digital wilderness for the British Library.

    • Jeremy Leighton John

Books and Arts

News & Views

  • News & Views |

    Simulations show that orbital chaos can lead to collisions between Earth and the inner planets. But Einstein's tweaks to Newton's theory of gravity render these ruinous outcomes unlikely in the next few billion years.

    • Gregory Laughlin
  • News & Views |

    Cells normally divide on reaching a fairly specific size, but how cell size dictates the timing of cell division remains obscure. In fission yeast, a spatial gradient of a cell-tip protein may provide an answer.

    • Kenneth E. Sawin
  • News & Views |

    Many plants introduced to new habitats have fewer microbial pathogens than when in their home range, and have the ability to grow rapidly. Such a combination may make for especially troublesome immigrants.

    • Tim Seastedt
  • News & Views |

    Diverse receptors on two types of cell mediate adaptive immunity in jawed vertebrates. In the lamprey, a jawless vertebrate, immunity is likewise compartmentalized but the molecular mechanics are very different.

    • Gary W. Litman
    •  & John P. Cannon
  • News & Views |

    Most syntheses in organic chemistry target one molecule, or a few closely related analogues at most. But by taking a leaf from nature's book, the latest synthetic strategy opens the door to a whole family of compounds.

    • Huw M. L. Davies
  • News & Views |

    The assembly of the proteasome — the cellular machine that eliminates unwanted proteins — is a carefully choreographed affair, involving a complex sequence of steps overseen by dedicated protein chaperones.

    • Kiran Madura

Reviews

  • Review Article |

    Observations of the Sun during total eclipses have led to major discoveries. A new generation of ground-based eclipse observations reaches spatial, temporal and spectral-resolution domains that are inaccessible from space.

    • Jay M. Pasachoff

Articles

  • Article |

    Variable lymphocyte receptors (VLRs) are used for antigen recognition in jawless vertebrates. Distinctive gene expression profiles for VLRA+ and VLRB+ lymphocytes in lampreys are now shown to resemble those of mammalian T and B cells, offering insight into the evolution of adaptive immunity.

    • Peng Guo
    • , Masayuki Hirano
    • , Brantley R. Herrin
    • , Jianxu Li
    • , Cuiling Yu
    • , Andrea Sadlonova
    •  & Max D. Cooper
  • Article |

    Yeast Sir2 deacetylates histone H4 lysine 16 and is known to have a role in ageing, but the exact mechanism is not known. Here, an age-associated decrease in Sir2 abundance is shown to be accompanied by an increase in H4 lysine 16 acetylation and loss of histones in replicatively old yeast cells, resulting in compromised transcriptional silencing.

    • Weiwei Dang
    • , Kristan K. Steffen
    • , Rocco Perry
    • , Jean A. Dorsey
    • , F. Brad Johnson
    • , Ali Shilatifard
    • , Matt Kaeberlein
    • , Brian K. Kennedy
    •  & Shelley L. Berger
  • Article |

    A class of enzymes known as alkyltransferase-like proteins (ATLs) can protect against alkylation damage to DNA. To gain insight into how this occurs, the structure of a yeast ATL has been solved in the presence and absence of damaged DNA, revealing that ATL flips the alkylated base out of the DNA helix, leaving the lesion to be acted on by proteins of the nucleotide excision repair pathway.

    • Julie L. Tubbs
    • , Vitaly Latypov
    • , Sreenivas Kanugula
    • , Amna Butt
    • , Manana Melikishvili
    • , Rolf Kraehenbuehl
    • , Oliver Fleck
    • , Andrew Marriott
    • , Amanda J. Watson
    • , Barbara Verbeek
    • , Gail McGown
    • , Mary Thorncroft
    • , Mauro F. Santibanez-Koref
    • , Christopher Millington
    • , Andrew S. Arvai
    • , Matthew D. Kroeger
    • , Lisa A. Peterson
    • , David M. Williams
    • , Michael G. Fried
    • , Geoffrey P. Margison
    • , Anthony E. Pegg
    •  & John A. Tainer

Letters

  • Letter |

    Of the 342 planets so far discovered orbiting other stars, 58 'transit' the stellar disk; the light from the star passes through the atmosphere of the planet, and in a few cases the basic atmospheric composition of the planet can be estimated. The transmission spectrum of our planet, obtained during a lunar eclipse, is now reported, with implications for the search to find analogues of Earth.

    • Enric Pallé
    • , María Rosa Zapatero Osorio
    • , Rafael Barrena
    • , Pilar Montañés-Rodríguez
    •  & Eduardo L. Martín
  • Letter |

    Here, numerical simulations of the evolution of the Solar System over 5 Gyr, including contributions from the Moon and general relativity, show that one per cent of solutions lead to a large increase in Mercury's eccentricity—large enough to allow collisions with Venus or the Sun. In one of these high eccentricity solutions, a subsequent decrease of Mercury's eccentricity leads to a destabilization of all the terrestrial planets about 3.34 Gyr from now, with possible collisions of Mercury, Mars or Venus with the Earth.

    • J. Laskar
    •  & M. Gastineau
  • Letter |

    The ability to electrically control the bandgap, a fundamental property of semiconductors and insulators that determines electrical and optical response, is highly desirable for device design and functionality. Experiments now demonstrate versatile control of the bandgap in bilayer graphene-based devices by use of electric fields.

    • Yuanbo Zhang
    • , Tsung-Ta Tang
    • , Caglar Girit
    • , Zhao Hao
    • , Michael C. Martin
    • , Alex Zettl
    • , Michael F. Crommie
    • , Y. Ron Shen
    •  & Feng Wang
  • Letter |

    Although organic chemists often devise synthetic routes for molecules by mimicking enzyme reactions, such syntheses generally target individual compounds; here, a strategy is reported that targets a whole family of compounds. The approach mimics the biosynthesis of terpenes to efficiently prepare five compounds from the eudesmane family of terpenes, and provides a framework for the synthesis of other such compounds.

    • Ke Chen
    •  & Phil S. Baran
  • Letter |

    Climate sensitivity models may inaccurately characterize the full Earth system response, as they ignore changes in the carbon cycle, aerosols, land use and land cover. A combination of a simplified climate model, a range of simulations from a recent model intercomparison and historical constraints now show that, independent of the timing of emissions or the atmospheric concentration of CO2, emitting a trillion tonnes of carbon will cause global warming of 1.0 to 2.1 degrees Celsius.

    • H. Damon Matthews
    • , Nathan P. Gillett
    • , Peter A. Stott
    •  & Kirsten Zickfeld
  • Letter |

    Large earthquakes have been observed to trigger other earthquakes as teleseismic waves pass by the region, and microearthquake activity has been shown to be modulated by seasonal atmospheric pressure variations. It is now shown that, in eastern Taiwan, slow earthquakes can be triggered by typhoons; lower pressure from the passing of the typhoon is thought to result in a small unclamping of the fault.

    • ChiChing Liu
    • , Alan T. Linde
    •  & I. Selwyn Sacks
  • Letter |

    The observation that midbrain dopamine neurons are activated by reward, or sensory stimuli predicting reward, has led to the hypothesis that they encode value-related signals and are inhibited by aversive events. This is now shown to be true for only a subset of dopamine neurons; by recording neuronal activity in monkeys, dopamine neurons are found to be more heterogeneous than this model would suggest.

    • Masayuki Matsumoto
    •  & Okihide Hikosaka
  • Letter |

    Reflex circuits are specifically formed between sensory and motor neurons based on the class of sensory cell and the muscle type innervated by the motor neuron. Here, this fine synaptic specificity is found to be mediated by selective expression of the class 3 semaphorin Sema3e and its high-affinity receptor plexin D1 (Plxnd1) by specific motor and sensory neuron populations, respectively.

    • Eline Pecho-Vrieseling
    • , Markus Sigrist
    • , Yutaka Yoshida
    • , Thomas M. Jessell
    •  & Silvia Arber
  • Letter |

    A chromosomal translocation found in certain acute myeloid leukaemia (AML) patients results in fusion of the plant homeodomain (PHD) finger of a chromatin-binding protein to a common fusion partner, nucleoporin-98 (NUP98). By binding chromatin, the NUP98–PHD fusion protein—found to be a potent oncoprotein that induces AML—apparently locks developmentally important genes into an active state.

    • Gang G. Wang
    • , Jikui Song
    • , Zhanxin Wang
    • , Holger L. Dormann
    • , Fabio Casadio
    • , Haitao Li
    • , Jun-Li Luo
    • , Dinshaw J. Patel
    •  & C. David Allis

    Collection:

  • Letter |

    Cells normally grow to a certain size before they enter mitosis and divide, and entry into mitosis is known to be dependent on the activity of Cdk1; however, how this is sensed remains unknown. Here, and in an accompanying paper, it is shown that an intracellular polar gradient of dual-specificity the tyrosine-phosphorylation regulated kinase (DYRK) Pom1 relays size information to the Cdk1 inhibitor Wee1.

    • Sophie G. Martin
    •  & Martine Berthelot-Grosjean
  • Letter |

    Cells normally grow to a certain size before they enter mitosis and divide, and entry into mitosis is known to be dependent on the activity of Cdk1; however, how this is sensed remains unknown. Here, and in an accompanying paper, it is shown that an intracellular polar gradient of dual-specificity the tyrosine-phosphorylation regulated kinase (DYRK) Pom1 relays size information to the Cdk1 inhibitor Wee1.

    • James B. Moseley
    • , Adeline Mayeux
    • , Anne Paoletti
    •  & Paul Nurse
  • Letter |

    The proteasome is a large proteolytic machine that degrades ubiquitin-tagged proteins. Substrates are recognized and unfolded by the regulatory particle (RP) and translocated into a central proteolytic chamber, called the core particle (CP), where degradation takes place. Here, and in a complimentary study, the pathway of RP assembly is elucidated, demonstrating that RP assembly is a highly orchestrated process.

    • Jeroen Roelofs
    • , Soyeon Park
    • , Wilhelm Haas
    • , Geng Tian
    • , Fiona E. McAllister
    • , Ying Huo
    • , Byung-Hoon Lee
    • , Fan Zhang
    • , Yigong Shi
    • , Steven P. Gygi
    •  & Daniel Finley
  • Letter |

    The proteasome is a large proteolytic machine that degrades ubiquitin-tagged proteins. Substrates are recognized and unfolded by the regulatory particle (RP) and translocated into a central proteolytic chamber, called the core particle (CP), where degradation takes place. Here, and in a complimentary study, the pathway of RP assembly is elucidated, demonstrating that RP assembly is a highly orchestrated process.

    • Soyeon Park
    • , Jeroen Roelofs
    • , Woong Kim
    • , Jessica Robert
    • , Marion Schmidt
    • , Steven P. Gygi
    •  & Daniel Finley
  • Letter |

    The biosynthesis of the naturally occurring compound phosphinothricin tripeptide (PTT) involves the conversion of 2-hydroxyethylphosphonate (HEP) to hydroxymethylphosphonate (HMP). This requires the cleavage of a C(sp3)–C(sp3) bond. Here, the X-ray crystal structure of the enzyme that catalyzes this reaction (hydroxyethylphosphonate dioxygenase, HEPD) is solved, and the mechanism of this remarkable transformation is explored.

    • Robert M. Cicchillo
    • , Houjin Zhang
    • , Joshua A. V. Blodgett
    • , John T. Whitteck
    • , Gongyong Li
    • , Satish K. Nair
    • , Wilfred A. van der Donk
    •  & William W. Metcalf

Futures

Naturejobs

  • Prospects |

    Despite the gloom, this isn't a bad time to begin a scientific career. Keep your nerve, Bart Noordam and Patricia Gosling advise.

    • Bart Noordam
    •  & Patricia Gosling
  • Careers Q&A |

    Blinded in 1984, geographer Reginald Golledge was this year named Faculty Research Lecturer by the University of California, Santa Barbara.

    • Virginia Gewin
  • Postdoc Journal |

    I want to hear that I have a job and that my manuscript's been accepted.

    • Bryan Venters
  • Career Brief |

    Lab techs at a new Maryland facility will work on adult-derived stem-cell therapies.

  • Career Brief |

    The promise of a nuclear renaissance has driven an increase in nuclear engineering degrees.

  • Career Brief |

    Pilot research grant aims to boost diversity of US biomedical workforce.

Brief Communications Arising

  • Brief Communications Arising |

    • Martin Wille
    • , Thomas F. Nägler
    • , Bernd Lehmann
    • , Stefan Schröder
    •  & Jan D. Kramers
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