SCIENCE OBSERVER
In the News
This roundup of notable recent items about scientific research,
culled from news reports, was compiled from Science in the
News Daily and Science in the News Weekly, free
electronic newsletters produced by Sigma Xi's Public
Understanding of Science program. Online: sitn.sigmaxi.org and www.americanscientist.org/sitnweekly
White Blood Cells Transfer Mouse's Resistance to
Cancer
The accidental discovery three years ago of a mouse that is immune
to cancer was startling by itself. Now the scientists who originally
identified that animal and bred others from it (dubbed
"spontaneous regression/complete resistance" or SR/CR
mice) have successfully transferred that resistance to normal mice
by infusing them with white blood cells from the SR/CR strain. The
treated mice retain cancer resistance for long periods by a
mechanism that still remains unknown.
Hicks, A. M. et al. Transferable anticancer innate
immunity in spontaneous regression/complete resistance
mice. Proceedings of the National Academy of Sciences of
the U.S.A. 103:7753–7758 (May 16)
Lessons Pay Off for Meerkat Pups
Zoologists have discovered that adult meerkats, small South African
members of the mongoose family, teach their pups how to eat
dangerous animals. When the offspring are quite small, adults bring
them dead animals (such as scorpions, lizards and spiders) on which
to practice. Then, as the pups get older, they are given disabled
prey. An adult might, for example, bite off the stinger of a
scorpion before presenting it to a pup. Eventually, the juvenile
graduates to handling normal, live prey. In tests, young meerkats
that gained experience wrangling scorpions in this way are more
capable than those that had practiced only on dead scorpions or
boiled eggs, which were used as a control.
Thornton, A., and K. McAuliffe. Teaching in wild meerkats.
Science 313:227–229 (July 14)
Protein Enhances Transfer of Pluripotency
Stem cells are said to be "pluripotent": They can develop
into any type of tissue in the body and thus hold great promise in
treating spinal cord injury, Parkinson's disease and other chronic
disorders. But obtaining embryonic stem cells requires the
destruction of human embryos, so research in this area raises
serious ethical concerns. New work identifies a protein (called
Nanog) that promotes the creation of pluripotent cells from the
fusion of a stem cell with a more specialized adult cell, such as a
neuron. This line of research may one day lead to methods that allow
adult cells to be converted to a pluripotent state without the use
of stem cells at all.
Silva, J., et al. Nanog promotes transfer of
pluripotency after cell fusion. Nature 441:997
– 1001 (June 22)
Anti-Allergy Drug Fights Malaria
Tests in mice reveal that astemizole, a drug developed to treat
allergies, kills the malaria parasite with high efficacy. Astemizole
is already licensed for use in people, so it could be rapidly
approved for use against malaria. And because the drug is no longer
under patent, the cost could be kept low.
Chong, C. R., et al. A clinical drug library screen
identifies astemizole as an antimalarial agent. Nature
Chemical Biology 2:415–416 (August 1)
Earliest Cultivar May Be the Fig
Near the city of Jericho in the West Bank, a team of two
archaeobotanists and an archaeologist have discovered what may be
the earliest traces of human agriculture. The charred remains of
nine small figs, found in the ruins of a burned building, are
estimated to be 11,400 years old. This variety of fig probably bore
sweet fruit but no fertile seeds, and thus it could have survived
only through artificial cultivation. Wheat, barley and chickpeas had
previously been thought to be the first crops, but these figs
predate those examples of early agriculture by a millennium.
Kislev, M. E, et al. Early domesticated fig in the
Jordan Valley. Science 312:1372–1374 (June
2)
Tiny Black Holes May Pervade Space
Most people think of black holes as supermassive objects, the
remnants of collapsed stars whose powerful gravity devours all
nearby matter. But some theories suggest that these strange objects
may be much more common—and much closer to home—than had
been thought. The solar system, for example, may contain 3,000 to
300,000 of these objects at a given time, some of them floating
inside the orbit of Mars. New work suggests that such objects would
produce interference fringes in the energy spectra of gamma-ray
bursts, a prediction that soon should be able to be tested.
Keeton, C. R., and A. O. Petters. Formalism for testing
theories of gravity using lensing by compact objects. III.
Braneworld gravity. Physical Review D 73:104032
(May 24)
Split Between Human and Chimp Lineages Was
Protracted
New genetic analyses indicate that the final split between the
earliest humans and chimpanzees occurred at most 6.3 million years
ago and probably less than 5.4 million years ago. To reconcile this
result with fossil evidence (which puts the time of divergence at
least a million years earlier), scientists suggest that early
hominids and chimps must have interbred for some period of time
before a final split occurred.
Patterson, N., et al. Genetic evidence for complex
speciation of humans and chimpanzees. Nature
441:1103–1108 (29 June)
Avian Flu Entered Nigeria Thrice
In February, health officials reported an outbreak of avian flu at a
large farm in southwest Nigeria where chickens, geese and ostriches
were being raised. The virus also turned up at two other places in
that country. Molecular biologists have now compared genetic
information obtained in all three locations and determined that the
outbreaks stemmed from three distinct viral strains, ones
genetically similar to those discovered in earlier outbreaks in
Egypt, Russia and Mongolia.
Ducatez, M. F., et al. Multiple introductions of
H5N1 in Nigeria. Nature 442:37 (July 6)
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