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Nature press release for 21 February issue

February 21, 2002

[415859] CLONING: MEET 'CC:', THE CARBON-COPY CAT (p859)
Researchers announce the birth of the first cloned cat, in a Brief Communication to Nature published online this week. The kitten, called 'Cc:' and now almost two months old, appears healthy and energetic, although she is completely unlike her tabby surrogate mother.
Mark Westhusin and colleagues at Texas A&M University, College Station, created Cc: by transplanting DNA from a female three-coloured (tortoiseshell or calico) cat into an egg cell whose nucleus had been removed, and then implanting this embryo into the surrogate mother. Cc:`s coat colour suggests that she is a clone, and a genetic match between Cc: and the donor mother confirms this, the researchers say. She is not, however, identical to her DNA donor. The reason for this is that the pattern on cats` coats is only partly genetically determined - it also depends on other factors during development.
Out of 87 implanted cloned embryos, Cc: is the only one to survive - comparable to the success rate in sheep, mice, cows, goats and pigs. If these odds can be shortened and Cc: remains in good health, pet cloning may one day be feasible.
CONTACT:
Please contact the authors via the Texas A&M University Office of Public Relations (tel +1 979 845 4641, e-mail cjl@univrel.tamu.edu, sjc@univrel.tamu.edu ) who are co-ordinating interviews with the authors.

[415871] `ALTERNATIVE` YEAST JOINS GENOME PARTY (pp871-880; N&V)
The minority fungus of lab culture - fission yeast Schizosaccharomyces pombe - is fighting back this week, with the announcement in Nature of its completed genome.
Researchers finished sequencing the DNA of its more popular cousin, the budding yeast Schizosaccharomyces cerevisiae, back in 1997. But S. cerevisiae and S. pombe are distant relatives that have evolved different ways to run their cells - so comparing the two can provide insights into the basics of cell biology.
        The genome of S. pombe contains the smallest number of protein-coding genes (4,824) so far seen in eukaryotes (organisms, including humans, whose cells contain a nucleus). At the same time, "some aspects of the genomic structure are more complex", says Paul Nurse of the Cancer Research UK in London, who led the sequencing effort. These include longer regions thought to control gene activity, and more introns, the non-protein-coding sections in genes.
        By comparing the genome with the other five eukaryote genomes completed - budding yeast, nematode worm, fruit fly, mustard weed and human - the team pulled out a selection of genes that may define a eukaryote`s essential functions. "Get ready everyone, because a fight for glory is brewing in the yeast family," says Jonathan Eisen of The Institute for Genome Research, Rockville, Maryland, in a related News and Views article.
CONTACT:
Paul Nurse tel +44 20 7269 3264, e-mail p.nurse@cancer.org.uk
Jonathan Eisen tel +1 301 838 3507, e-mail jeisen@tigr.org

A press conference (held under embargo conditions) at which Paul Nurse will present his work will be held at 11.00 on Monday 18 February at Cancer Research UK, 61 Lincoln's Inn Fields, London, WC2.
For further information, please contact Tony Stephenson tel +44 20 7269 2970, e-mail a.stephenson@cancer.org.uk

[415893] RELICS: KEEPING VASA SHIPSHAPE (pp893-897; N&V)
The Vasa is a seventeenth-century wooden warship in a remarkable state of preservation. Sunk on her maiden voyage in 1628 and salvaged in 1961, she has been on display in a Stockholm museum since 1989.
Now, Magnus Sandström of University of Stockholm, Sweden, and colleagues have found large quantities of sulphur inside the Vasa`s timbers. In a Letter to this week's Nature, they describe how this sulphur is sufficient to make 5,000 kilograms of sulphuric acid if fully oxidized. Indications that the rusting remains of 8,500 bolts are responsible for catalysing this oxidation suggest that conservation methods should focus on making the iron inert, or removing it altogether.
CONTACT:
Magnus Sandström tel +46 793 846 214, e-mail magnuss@struc.su.se
Jim Gillon, Nature editor, tel +44 20 7843 4554, e-mail j.gillon@nature.com

[415883] TECHNOLOGY: BROADBAND LASER BUILT (pp883-887)
Bell Labs researchers have made a laser that emits light over an extremely wide wavelength range. The device should find uses from communications to spectroscopy.
        As they explain in this week`s Nature, Claire Gmachl and colleagues of Lucent Technologies, Murray Hill, New Jersey, have built a mid-infrared laser, based on a stack of semiconductor layers, that emits with constant intensity over a broad range of wavelengths, with none of the drawbacks of previous attempts at broadband laser action.
The semiconductor laser has a quantum cascade configuration. The various semiconductor layers in the stack each have a slightly different energy structure and a number of optical excitations throughout the cascade cooperate in order to provide broadband optical gain from 5 to 8 micrometre wavelength.
CONTACT:
Claire Gmachl tel +1 908 582 6164 (from Monday 17 February), e-mail cg@lucent.com

[415835] POLICY: COMPROMISED PRINCIPALS (pp835-836)
This week's Commentary in Nature finds experienced biochemist Peter A. Lawrence of the MRC Laboratory of Molecular Biology, Cambridge, UK, less than impressed with the way that the `principal investigator` role has evolved in today's scientific community. The `system`, writes Lawrence, supports the natural tendency of the experienced to take advantage of the inexperienced, and helps ensure that credit always flows up the ladder of rank. And the exponential rise in the secondary literature perpetuates the `star name` culture. Young scientists, though, could change the situation by being less timid and `careerist` in their attitude to research, he proposes.
CONTACT:
Peter A. Lawrence tel +44 1223 402282, available week beginning Monday 18 February on +1 510 642 5014, e-mail pal@mrc-lmb.cam.ac.uk

[415887] TECHNOLOGY: 3D X-RAY IMAGING (pp887-890; N&V)
Micrometre-scale X-ray imaging is a valuable tool from medicine to crystallography, but it has been restricted to two dimensions. Now a clever modification takes us into the third dimension, as this week`s Nature reveals.
B. C. Larson and colleagues of Oak Ridge National Laboratory, Tennessee, have combined the atomic-scale sensitivity of X-ray diffraction with the three-dimensional imaging of X-ray tomography to create 'differential aperture X-ray microscopy' (DAXM). The technique maps local crystal structure, orientation and distortion before, during and after deformation.
The availability of such information should provide "a new impetus and critical tests" for further developments of materials science theory and multi-scale modelling, says G. S. Cargill III of Lehigh University, Bethlehem, Pennsylvania, in an accompanying News and Views article.
CONTACT:
Bennett Larson tel +1 865 574 5506, e-mail bcl@ornl.gov
Slade Cargill tel +1 610 758 4207, e-mail gsc3@lehigh.edu

[415905] LIFELINES: CLIMATE CHANGE AND MALARIA (pp905-909)
There is no link between climate change and the growth of malaria in upland areas of East Africa, say researchers in this week`s Nature. Simon Hay of the University of Oxford, UK, and colleagues looked at climate data spanning 1901-95 for four regions in Kenya, Uganda, Rwanda and Burundi. They found no significant trends in temperature, rainfall or the number of months when conditions were suitable for malaria transmission.
The researchers conclude that something other than global warming must have fuelled the rise of malaria in the past two decades, such as the growth of drug resistance, or the possibility that health care has not kept pace with population growth. Drawing simplistic links between global climate change and local disease patterns could lead to policy mistakes, they conclude.
CONTACT:
Simon Hay (currently in Nairobi) tel +254 2 720163, e-mail simonhay@wtnairobi.mimcom.net or simon.hay@zoo.ox.ac.uk

[415860] PHYSICS: OXYGEN DROPS UP (p860)
In a famous physics demonstration, a magnet levitates, suspended in a magnetic field, over a superconductor cooled using liquid nitrogen to 77 Kelvin (-196 degrees Celsius).
If that wasn`t weird enough, in a Brief Communication to this week`s Nature by D. P. Hampshire and colleagues from the University of Durham, UK, report another bizarre gravity-defying feat associated with the demonstration. They observed liquid oxygen dripping upwards from the semiconductor onto the magnet, where it then boiled to oxygen gas and disappeared.
Their explanation is that oxygen (its boiling point is higher than nitrogen`s) is condensing out of the air onto the surface of the very cold superconductor. Because liquid oxygen is slightly magnetic, it is then drawn - against the force of gravity - towards the magnet. Warned by the magnet, the oxygen droplet then boils back into the air before being immediately replaced by another oxygen drop from below.
CONTACT:
Damian Hampshire tel +44 191 374 2184, e-mail d.p.hampshire@durham.ac.uk

[415926] LIFELINES: ANTI-PARASITE DRUG LEAD (pp926-929; N&V)
The cause of many of the world's most crippling diseases, parasitic organisms often know our inner workings better than we do ourselves. Having given up their independence over time, they now rely on getting an easy meal at the expense of their hosts. Only when necessary have they retained the molecular mechanisms needed to generate the basic building blocks of life.
                        In this week`s Nature Barbara A. Fox and David J. Bzik of Dartmouth Medical School, Lebanon, New Hampshire, show how an understanding of these mechanisms can provide us with new ways of fighting parasitic infections. By knocking out one biosynthetic pathway in the bird and mammal parasite Toxoplasma gondii (a distant relative of the one that causes malaria), Fox and Bzik have produced severely weakened strains that cannot survive when injected into mice.
                Better still, the mutant parasites stimulate a potent immune response that protects the mice from later infection with the wild-type parasite. The findings have implications for designing drugs to combat parasitic infections, and may offer a new vaccination approach.
                "These results may finally allow safe, reliable vaccination programmes in livestock such as sheep and cattle - the benefits could be immense," says L. David Sibley of Washington University School of Medicine, St Louis, Missouri, in an accompanying News and Views article.
CONTACT:
David J. Bzik tel +1 603 650 7951, e-mail david.j.bzik@dartmouth.edu
L. David Sibley tel +1 314 362 7059, e-mail sibley@borcim.wustl.edu

[415853] POLICY: NUCLEAR WARHEAD SCIENCE PROGRAMME REVIEWED (pp853-857)
In a Feature this week in Nature, Keith O'Nions and Robin Pitman of the Ministry of Defence, London, and Clive Marsh of Atomic Weapons Establishment, Aldermaston, Reading, UK, set out the elements of the nuclear warhead science programme that will underpin future assessments of the safety and performance of Britain`s warheads in compliance with treaty obligations.
        A scientific methodology is now being developed, without further nuclear tests, aimed at underwriting the safety and performance of the ageing Trident stockpile with continued high confidence, they explain. The approach builds on previous nuclear test experience and seeks to replace the requirements for further empirical test data by developing a deeper theoretical and experimental understanding of the relevant fundamental science. This must then be drawn together and applied to the nuclear warhead system using intensive numerical modelling.
This new approach will continue to demand high calibre scientists and engineers, supported by modern experimental techniques and diagnostics, underpinned by state-of-the-art supercomputing and visualization facilities. Thes article describes the challenge and Britain's response to it.
CONTACT:
Keith O'Nions (available on Tuesday 19 February) tel +44 20 7218 6588, e-mail csa/pa@mod.gsi.gov.uk

[415861] AND FINALLY: CLIMATE: POLLUTED AIR (p861)
Flying into a major city in summertime, you may have noticed a blanket of polluted air hanging in a discrete layer over the area. These smog layers - confined by layers of air at different temperatures above and below - are a well studied phenomenon.
In a Brief Communication to this week`s Nature, Peter Hobbs at the University of Washington in Seattle reports on the existence of the exact opposite. Flying over southern Africa, he observed layers of perfectly clean air, trapped between dirty blankets of pollution.
The clean air `slots` are only a few hundred metres thick and located at heights of about 2 kilometres. Hobbs suspects these are layers of very dry stable air that can be enveloped by polluted air but does not mix with it.
CONTACT:
Peter Hobbs tel +1 206 543 6027, e-mail phobbs@atmos.washington.edu

ALSO IN THIS ISSUE
? The role of the thermohaline circulation in abrupt climate change
? Diverse supernova sources of pre-solar material inferred from molybdenum isotopes in meteorites
? Chiral recognition in dimerization of adsorbed cysteine observed by scanning tunnelling microscopy
? Transient dynamics of vulcanian explosions and column collapse
? Global environmental controls of diversity in large herbivores
? Numerical representation for action in the parietal cortex of the monkey
? BH3-only Bcl-2 family member Bim is required for apoptosis of autoreactive thymocytes
? A Rad26-Def1 complex coordinates repair and RNA pol II proteolysis in response to DNA damage
? Structural basis for acidic-cluster-dileucine sorting-signal recognition by VHS domains
? Structural basis for recognition of acidic-cluster dileucine sequence by GGA1
? Self-shielding in the solar nebula

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