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Article Released Wed-22nd-March-2006 18:40 GMT
Contact: Ruth Institution: Nature Publishing Group
 Protected areas will not be enough to save Amazon; Rice pathogen scrutinized; Alzheimer's protein player exposed; Squeezing light onto chips; Down's syndrome; Antarctic ice core secrets; Plant promiscuity…

Summaries of newsworthy papers from Nature. Vol.440 No.7083 Dated 23 March 2006


This press release is copyright Nature. VOL.440 NO.7083 DATED 23 MARCH 2006

This press release contains:
* Summaries of newsworthy papers:
* Conservation biology: Protected areas will not be enough to save Amazon
* Agriculture: Rice pathogen scrutinized
* Brain: Alzheimer's protein player exposed
* Photonics: Squeezing light onto chips
* Genetics: Down's syndrome
* Climate: Antarctic ice core secrets
* And finally...Plant promiscuity over-hyped
* Mention of papers to be published at the same time with the same embargo
* Geographical listing of authors

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[2] Conservation biology: Protected areas will not be enough to save Amazon
(pp 520-523)

Public wildlife reserves will not be enough to prevent the Brazilian Amazon
from excessive deforestation, according to new conservation predictions.
Without measures that also prevent the destruction of tropical rainforest on
private land, about 40% of the Amazonian forest will be lost by 2050.
Cattle ranching and soy production are boom industries that threaten to
destroy much of Brazil's natural forest, say Britaldo Silveira Soares-Filho
and colleagues in this week's Nature. They argue that, in addition to the
establishment of publicly protected parks, farmers should be forced to meet
guidelines certifying that they are managing their land in a sustainable
way. Failure to do so would deny them access to lucrative international
markets for their produce.

The authors add that without such a strategy, conservation prospects are
bleak. They used a computer model to predict future trends under a range of
different conservation practices. If deforestation is allowed to continue
unchecked, eight of the Amazon River's twelve major watersheds will lose
more than half of their forest cover, and almost 100 of the region's native
mammal species will lose over 50% of their habitat.

Britaldo Soares-Filho (Universidade Federal de Minas Gerais, Minas Gerais, Brazil)
Tel: +55 313 499 5417; E-mail:

[3] Agriculture: Rice pathogen scrutinized (pp 535-539)

In this week's Nature, Nicholas Talbot and his colleagues reveal how the
rice blast fungus Magnaporthe grisea, a major pathogen of cultivated rice
and a threat to food security, invades the rice plant.

From the genetic sequence data of this fungus, it seems that secreted
peptides might underlie its pathogenicity. The Talbot team show that a
protein in the fungi's protein-processing Golgi apparatus called MgAPT2 is
necessary for secretion. The fungus uses small cellular sacs derived from
the Golgi apparatus to transport virulent fungal peptides to the exterior of
the plant cell. These peptides then help the fungus to gain entry into the
plant cells so that it can spread through the plant tissue. MgAPT2 is also
required in order for plant cells to launch a defensive response.

Nicholas Talbot (University of Exeter, Exeter, UK)
Tel: + 44 1392 264 673; E-mail:

[4] Brain: Alzheimer's protein player exposed (pp 528-534)

In this week's Nature, researchers reveal how an enzyme called Pin1 plays a
part in the pathogenesis of Alzheimer's disease. Brain plaques, consisting of amyloid-beta peptides derived from amyloid precursor protein (APP), are one hallmark of Alzheimer's disease. Kun Ping Lu and his colleagues present evidence that Pin1 regulates the
processing of APP into toxic forms of amyloid- beta.

The team show that Pin1 directly binds to a specific region in APP,
boosts-by 1,000-fold-its conversion from one conformation to another, and
seems to suppress the production of amyloid- beta 42, a particularly toxic
form of amyloid- beta. Further studies on this conformational change may
help clarify the molecular events leading to Alzheimer's, the authors say.

Kung Ping Lu (Harvard Medical School, Boston, MA, USA)
Tel: +1 617 667 4143; E-mail:

[5] Geology: The oldest evidence of methane makers (pp 516-519; N&V)

Methanogenic microbes - methane-making micro-organisms - are thought to be
among Earth's earliest life forms. Exactly when they first appeared, though,
has always been uncertain. No one has been able to find direct geological
evidence to support the hypothesis that they existed in the Archaean era,
3.8 to 2.5 billion years ago.

But as reported in this week's Nature, Yuichiro Ueno and colleges
have been busy. The Japanese researchers have found evidence of
methane-bearing fluid inclusions in about 3.5-billion-year-old hydrothermal
precipitates from the Pilbara craton in Western Australia. Their analyses -
through carbon isotope composition - indicate the methane is of microbial

It is the oldest evidence of methanogen existence, pre-dating
previous circumstantial geochemical evidence by about 700 million years.
Microbial methane may have been important in regulating the climate on the
Archaean Earth - potentially providing sufficient amounts of the greenhouse
gas to mitigate the severely frozen conditions.

Yuichiro Ueno (Tokyo Institute of Technology, Yokohama, Japan)
Tel: +81 45 924 5142; E-mail:

Don Canfield (Odense University, Odense, Denmark)
Tel: +45 6550 2751; E-mail:

[6] Photonics: Squeezing light onto chips (pp 508-511; N&V)

A new family of devices for guiding and processing light signals in
chip-based information technology is unveiled in this week's Nature by
Sergey Bozhevolnyi and his colleagues. These miniaturized structures should
help to overcome one of the main obstacles to making a compact 'photonic'
technology comparable to that of microelectronics: the difficulty of
manipulating light at very small scales.

The key problem for 'microphotonics' is that light can only be transmitted
properly through channels and holes that are wider than its wavelength. In
today's fibre-optic telecommunications, wavelengths of about 1.5 micrometres
(thousandths of a millimetre) are used, and that's a lot bigger than the
channels along which electrons are guided on present-day silicon chips.
But there is an alternative. Light waves can be used to excite collective,
wavelike motions of electrons on the surface of metals, known as surface
plasmons, which aren't restricted by this size limit. Bozhevolnyi and
colleagues have shown previously that some of these plasmons can move, in
the form of linked light and electron waves, along the bottom of V-shaped
grooves in a metal that are much narrower than the wavelength of the light.
They have now shown that such channels can be shaped so that they act as
photonic devices for splitting and modifying light signals. The researchers
have built a number of devices common in photonic technology, such as beam
splitters, from these V-shaped channels, and shown that they work well for
infrared light signals at the standard telecom wavelength.

Sergey Bozhevolnyi (Aalborg University, Aalborg East, Denmark)
Tel: +45 9635 9222; E-mail:

Francisco Garcia-Vidal (Universidad Autonoma de Madrid, Madrid, Spain)
Tel: +34 914 978 515; E-mail: <>

[7] Genetics: Down's syndrome (AOP)
DOI: 10.1038/nature04678

***This paper will be published electronically on Nature's website on 22
March at 1800 London time / 1300 US Eastern time (which is also when the
embargo lifts) 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 23 March, but at a later date.***

Down's syndrome is caused by having three (rather than two) copies of
chromosome 21, but researchers know little about how a 1.5-fold increase in
gene dosage on this chromosome triggers the various developmental problems
associated with Down's syndrome.
In a study published online by Nature, Gerald Crabtree and his colleagues
make an important step towards answering that question. They show that two
genes on chromosome 21, called DSCR1 and DYRK1A, work together to export
from the cell nucleus - and reduce the activity of - a group of NFAT
proteins that are critical for gene regulation during vertebrate growth and

The authors found that mice with mutations in Nfat genes show many of the
characteristics of Down's syndrome. NFAT proteins normally operate under a
positive feedback loop, enhancing their own production. The researchers used
mathematical modelling and studies of genetically engineered mice to show
that a 1.5-fold increase in DSCR1 and DYRK1A gene dosage produces a
disproportionately large reduction in NFAT activity. The feedback loop means
that an initially small reduction in NFAT grows into a larger one, leading
to decreased activation of NFAT target genes.

Gerald Crabtree (Stanford University School of Medicine, Stanford, CA, USA)
Tel: +1 650 723 8391; E-mail:

[8] Molecular nanotechnology: Pedal power (pp 512-515)

A set of molecular pedals that is powered by light and twists another
molecule is reported in Nature this week by Takuzo Aida and co-workers. The
molecule-sized device extends previous work on 'molecular machines' by
showing how motion induced in one component can be transferred to another.

Several research groups have shown that molecules that change shape
when irradiated with light can be used to create molecular motors and other
devices with moving parts. But in order to carry out useful tasks with such
minuscule components, they will probably have to be linked up to other
molecules, in much the same way as the mechanical motions of pistons in a
car engine are transferred via crankshafts and gears to the wheels.

Aida and colleagues have made a set of molecular pedals in which the
absorption of light in one part of the molecule introduces a kink which
drives the scissor-like swivelling of the pedal units around a kind of
molecular ball-bearing. The challenge was then to transfer this swinging
motion to another molecule, which they did by designing the pedals so that
they trapped a 'guest' molecule between them. When the pedals swivelled, the
guest molecule became twisted. The researchers suggest that sequences of
such interlocking motions might allow remote control of molecular-scale

Takuzo Aida (The University of Tokyo, School of Engineering, Tokyo, Japan)
Tel: +81 3 5841 7251; E-mail:

[9] Climate: Antarctic ice core secrets (pp 491-496)

Chemical data from an ice core over three kilometres long provide an insight
into past climatic conditions over eight glacial cycles, Eric Wolff and
colleagues report in this week's Nature.

Measurements from the Dome C Antarctic ice core constrained three
environmental parameters over the past 740,000 years: winter sea-ice extent
in the Indian Ocean, biogenic productivity in the Southern Ocean and
climatic conditions in Patagonia.

Their results suggest that over large timescales, sea-ice extent was
closely tied to Antarctica temperature, and that sulphur compounds were not
active in climate regulation. A change occurs in the amplitude of Antarctic
temperature variations 440,000 years ago, but they discovered no associated
changes in internal climatic feedbacks.

Eric Wolff (British Antarctic Survey, Cambridge, UK)
Tel: + 44 1223 221491; E-mail:

[10] And finally...Plant promiscuity over-hyped (pp 524-527)

'Botanical horror stories' of cross-breeding in species, such as in
dandelions, oaks and blackberries, are dismissed by a paper in this week's
Nature, which proves that there are pure plant species lurking in the
undergrowth. Previously, many botanists have believed that the concept of
'species' cannot be applied to plants, but this research demonstrates that
they are more likely to produce reproductively independent lineages than

Rieseberg and colleagues set out to prove the 'innocence' of plants
by looking at phenetic and/or crossing relationships in over 400 genera of
plants and animals. The authors focus on a particular taxonomic problem -
naming clusters of individuals that are phenotypically different, but
genetically the same. They conclude that, contrary to popular belief, the
clusters most likely arise from factors such as asexual reproduction and
over-differentiation by taxonomists, rather than hybridization between
distinct, sexual species.

Although other factors, such as the development of seeds without
fertilization, will continue to cause problems for botanists, they can now
relax in the knowledge that there are discrete entities of plants that
correspond to reproductively independent lineages existing at the species

Loren Rieseberg (Indiana University, Bloomington, IN, USA)
Tel: +1 812 855 7614; E-mail:


[11] Human chromosome 11 DNA sequence and analysis including novel gene
identification (pp 497-500)

[12] Significant primordial star formation at redshifts z < 3-4 (pp

[13] A non-spherical core in the explosion of supernova SN 2004dj (pp

[14] An excitable gene regulatory circuit induces transient cellular
differentiation (pp 545-550)

[15] CHIP-mediated stress recovery by sequential ubiquitination of
substrates and Hsp70 (pp 551-555)

[16] RNA-mediated response to heat shock in mammalian cells (pp 556-560)

[17] Endonucleolytic cleavage of eukaryotic mRNAs with stalls in
translation elongation (pp 561-564; N&V)

[18] Human role in Russian wild fires (pp 436-437)


***These papers will be published electronically on Nature's website on 22
March at 1800 London time / 1300 US Eastern time (which is also when the
embargo lifts) as part of our AOP (ahead of print) programme. Although we
have included them on this release to avoid multiple mailings they will not
appear in print on 23 March, but at a later date.***

[19] Global landscape of protein complexes in the yeast Saccharomyces
DOI: 10.1038/nature04670

[20] A voltage-gated proton-selective channel lacking the pore domain
DOI: 10.1038/nature04700


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.

Belo Horizonte: 2
Para: 2

Quebec: 11
Toronto: 19

Taiwan: 4
Shanghai: 4

Aalberg Ost: 6
Copenhagen: 9

St Martin d'He'res: 9
Strasbourg: 6

Bremerhaven: 9
Heidelberg: 9

Dublin: 19

Haifa: 16

Florence: 9
Ispra: 18
Venice: 9

Ikoma: 19
Kawaguchi: 1, 5
Kyoto: 7
Sendai: 1
Tokyo: 11, 1, 8, 5
Tottori: 1
Yokohama: 5, 11

Daejeon: 11

Terrassa: 14

Stockholm: 9

Bern: 9

Cambridge: 9, 11
Exeter: 3
London: 11

Tuscan: 17
Berkeley: 13
Pasadena: 13, 14
San Diego: 13
San Francisco: 19
Stanford: 7
New Haven: 2, 19
Atlanta: 4
Bloomington: 10
Boston: 4, 20
Cambridge: 11, 19, 20
Woods Hole: 2
St Louis: 19
New York
Greenvale: 16
New York: 12, 16
North Carolina
Chapel Hill: 15
Cleveland: 16
Philadelphia: 12
University Park: 13
Seattle: 11

For North America and Canada
Katie McGoldrick, Nature Washington
Tel: +1 202 737 2355; E-mail:

For Japan, Korea, China, Singapore and Taiwan
Rinoko Asami, Nature Tokyo
Tel: +81 3 3267 8751; E-mail:

For the UK/Europe/other countries not listed above
Ruth Francis, Nature London
Tel: +44 20 7843 4562; E-mail

Zoe Corbyn, Nature London
Tel: +44 20 7843 4658; E-mail:

Victoria Picknell, Nature, London
Tel: +44 20 7843 4502; E-mail:

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