Transcript
Page 1: Monkey clones lead the way

60 SECONDS

Stem cells vetoed again

For the second time, President Bush

has vetoed legislation that would have

expanded US federal funding for

research on human embryonic stem

cells (ESCs). Neither house of Congress

can muster the two-thirds majority

needed to override the veto, delivered

on 20 June, but Democrats plan to

attach the measure to other bills.

Polls indicate a majority of Americans

back ESC research, so the move is likely

to stoke controversy in the coming

presidential election campaign.

Herbal cold remedy

A cure for the common cold? Not quite,

but the herbal supplement echinacea

can help reduce the chances of catching

the sniffles by 60 per cent, according to a

review of 14 studies into its effectiveness.

On average, it can also cut the time a

cold lasts by 1.4 days (The Lancet Infectious Diseases, vol 7, p 473).

Seal sickness strikes

At least 41 harbour seal pups off the

Danish coast have died of distemper,

raising fears that thousands more could

perish if the disease spreads. Previous

outbreaks killed half the harbour seal

population of northern Europe.

Space station open house

NASA plans to open up the International

Space Station to outsiders, its officials

said on Monday. The agency is in talks

with private and government

institutions who might want to run

microgravity experiments on the ISS.

Bioweapon bug escape

Texas A&M University failed to report

that three of its biodefence researchers

fell ill with Q fever in April 2006,

according to documents released under

the Freedom of Information Act. How

they contracted the disease is not

known, but the lab they work in tests

aerosols of the Coxiella burnetii bacterium, a potential bioweapon that

causes the disease. Earlier this year, the

university was fined for not disclosing

another researcher had become infected

with Brucella bacteria in February 2006.

proton beams and make them

collide at four points along the 27-

kilometre tunnel. The damaged set

of triplets is being repaired, while

the rest are being rejigged in situ.

CERN engineers only recently

cooled the first eighth of the LHC’s

ring of superconducting magnets –

about 4500 tonnes of material – to

its operating temperature of

1.9 kelvin. The job “took us a little

longer than planned”, says

Jos Engelen, CERN’s chief scientific

officer. The remaining magnets

have yet to be cooled, and Engelen

says that there isn’t much slack

left in the schedule. “The

engineers call this a success-

loaded schedule,” he says. “You

cannot have any other mishaps.”

IF EARTH’S interior were to cool

down, New York and Los Angeles

would end up hundreds of metres

under water. North America, it

seems, is being kept afloat by the

heat beneath the continent.

Derrick Hasterok and David

Chapman at the University of

Utah in Salt Lake City were

studying how bumps form in the

Earth’s crust and upper mantle.

One cause for the differences in

elevation is the buoyancy of

rocks: the less dense the rock, the

higher it rises. Until now it had

been assumed that density varied

only according to the type of rock.

Hasterok and Chapman created

models of North America to see if

temperature also had a part to

play in altering the rocks’ density.

By accounting for the effects of

rock type and thickness they were

able to determine how much of a

region’s buoyancy comes from

expansion caused by heat.

“It turns out about half of the

elevation is due to temperature,”

says Hasterok. The heat comes

from Earth’s interior, tectonic

plate movement and the decay of

radioactive elements in the crust.

Without the heat, much of North

America would be submerged.

Even Denver, the “mile-high city”,

would lie 222 metres below sea

level (Journal of Geophysical Research, vol 112, p B06414).

SHRUGGING off accusations of

rampant industrial pollution and

the news that it has overtaken the

US as the world’s largest carbon

emitter, China last week unveiled a

conservation strategy for its flora.

The country is home to 10 per

cent of all known plant species –

half of those unique to China –

and about 5000 species are under

threat. The initiative involves a

novel collaboration between three

state agencies and London-based

Botanic Gardens Conservation

International. The plan is to

safeguard China’s plant diversity

by allowing 15 million hectares of

farmland to revert to forest over

the next three years, extending

nature reserves, protecting

biodiversity hotspots and setting

up a plant monitoring system.

Farmland will also be managed to

support wild plant conservation.

“The Chinese government is

working hard to develop the

economy and improve our

sustainable environmental

practices,” says Jia Jiansheng of

the department of wildlife

conservation in the State Forestry

Administration, Beijing.

“Fifteen million hectares of farmland will revert to forest over the next three years”

Human therapeutic cloning has moved

one step closer to reality. Stem cells have

been extracted from cloned monkey

embryos for the first time – and if it

works in monkey cells, why not in

human cells too?

“It’s proof of principle for human

therapeutic cloning,” says team member

Don Wolf of the Oregon National

Primate Research Center in Beaverton.

Wolf’s colleague Shoukhrat Mitalipov

announced the breakthrough on 18 June

at a meeting of the International Society

for Stem Cell Research in Cairns,

Queensland, Australia. The Oregon team

stripped the chromosomes from 278

rhesus monkey eggs and replaced them

with the nuclei of skin cells from male

monkeys. They derived two stem-cell

lines from 21 embryos that developed

into a hollow ball of cells known as

a blastocyst.

Earlier cloning attempts in monkeys

used ultraviolet light as a guide while

the chromosomes were being removed

from eggs. The Oregon researchers

believe this damaged the resulting

embryos. Instead, their technique uses

polarised light to visualise the egg’s

interior (Human Reproduction, DOI:

10.1093/humrep/dem136).

The Oregon team has yet to show its

cells have all the characteristics of

embryonic stem cells. But already, other

researchers are planning to try the same

methods on human cells. “The primate

stuff really does give us renewed hope,”

says Renee Reijo Pera, who heads a

team working on therapeutic cloning at

Stanford University in California.

MONKEY CLONES LEAD THE WAY

PETE

OXF

ORD/

MIN

DEN

–Beat you to the stem cells–

America afloat

Chinese remedy

www.newscientist.com 30 June 2007 | NewScientist | 7

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