Nobel prizes honor innovative approaches

Looking into a worm, detecting X rays and tiny particles, and examining biomolecules

The 2002 Nobel prizes announced early this week pay tribute to an international sampling of scientists who have developed powerful new tactics for expanding the horizons of research.

WORM WIN. Work on how this worm arises from a single fertilized egg earned the prize. Erik Jorgensen
SUPERNOVA DEBRIS. The Chandra Observatory captured this X-ray image of the remnants of an exploding star. The colors show different energies. NASA/CXC/SAO

Physiology or Medicine

The German philosopher Friedrich Nietzsche once wrote, “You have made your way from worm to man, and much within you is still worm.” Offering ample support for that premise, this year’s Nobel Prize in Physiology or Medicine goes to three scientists whose anatomical and genetic studies of the nematode worm Caenorhabditis elegans revealed aspects of development relevant to all animals, including people.

The honored trio is Sydney Brenner of the Molecular Sciences Institute in Berkeley, Calif., H. Robert Horvitz, a Howard Hughes Medical Institute investigator at the Massachusetts Institute of Technology, and John E. Sulston of the Sanger Institute in Hinxton, England.

“The Laureates have identified key genes regulating organ development and programmed cell death and have shown that corresponding genes exist in higher species, including man,” declared the award statement released by the Nobel Assembly at the Karolinska Institute in Sweden.

In the 1960s, Brenner decided that C. elegans should be added to the small menu of animals that scientists regularly select for their studies. Brenner argued that the millimeter-long worm offers an excellent opportunity to study the development of an animal, particularly the wiring of its nervous system.

At the time, many biologists thought that investigating a lowly nematode was foolhardy. Brenner had a raft of reasons, however. The worm is transparent, grows rapidly, and contains exactly 959 cells, excluding sperm and eggs. And since C. elegans comes in hermaphroditic forms, it can mate with itself, creating inbred worms that enable biologists to identify genes and their roles more easily.

Today, there’s a strong community of worm researchers whose findings rival those of biologists studying the mouse and fly, two other common lab animals. In fact, 4 years ago, the worm became the first animal to have all of its genes sequenced and identified (SN: 12/12/98, p. 372: http://www.sciencenews.org/sn_arc98/12_12_98/Fob1.htm).

Horvitz and Sulston were among the earliest converts to C. elegans. Both worked in Brenner’s laboratory before starting their own teams. Sulston painstakingly documented the fate of each and every worm cell as the animal matured from a single egg cell. In doing so, he discovered, among many other things, that more than a hundred cells are destined to die during the tiny animal’s development, a phenomenon known as programmed cell death, or apoptosis.

“He had the great foresight to see that this description [of cell fate] could be powerful,” says Paul Sternberg of the California Institute of Technology in Pasadena, who has done similar cell-fate studies in worms.

Horvitz specialized in identifying worm genes that control biological processes, ranging from olfaction to apoptosis. His discovery of C. elegans genes related to apoptosis led to the identification of similar genes in people. The actions of such cell-death genes are now seen as critical to understanding human biology and many disease processes.

Horvitz’s work “took cell death to a new level,” says worm researcher Donald L. Riddle of the University of Missouri in Columbia.

When it comes to C. elegans research, the three new Nobel laureates “really set up the field,” says Sternberg. “They’re all wonderful, deep scientists.”

Physics

Scientists who designed novel detectors to probe some of the most violent actions of stars and most elusive features of the universe earned this year’s Nobel Prize in Physics.

Raymond Davis Jr. of the University of Pennsylvania in Philadelphia and Masatoshi Koshiba of the University of Tokyo shared half the prize for their pioneering work in detecting neutrinos emitted by the sun. The other half went to Riccardo Giacconi of Associated Universities in Washington, D.C., for discovering sources of X rays beyond the solar system.

“I’m delighted to hear of this award,” says astrophysicist John P. Hughes of Rutgers University in Piscataway, N.J. “It is well deserved all around.”

Of the fundamental particles of matter, neutrinos are among the most plentiful–and the most evasive. Originally thought to have no mass, neutrinos barely interact with other forms of matter, making them extremely difficult to detect.

Despite poor odds, Davis devised an experiment to spot neutrinos sent Earthward from nuclear reactions in the sun. Gathering data from the 1960s until 1994, his apparatus consisted of a tank filled with 100,000 gallons of dry-cleaning fluid. It sat 4,800 feet underground in the Homestake Gold Mine in South Dakota. Because this experiment detected fewer neutrinos than theoretically predicted, it was the first to suggest that some neutrinos disappear on their way to Earth (SN: 6/23/01, p. 388: Physics Bedrock Cracks, Sun Shines In).

In the 1980s, Koshiba and his team built the enormous Kamiokande detector in Japan and confirmed Davis’ solar-neutrino results (SN: 4/30/88, p. 277). The Kamiokande detector also observed a burst of neutrinos from the explosion of a star–supernova 1987A–in a neighboring galaxy (SN: 3/14/87, p. 165). A later, larger detector, Super-Kamiokande, provided evidence that neutrinos don’t disappear but instead change into a type indiscernible in earlier experiments (SN: 1/30/99, p. 76).

X rays furnish a portrait of other aspects of the universe. In 1959, Giacconi worked out how to construct a rocket-borne X-ray telescope. He and his group detected the first X-ray source outside the solar system–a distant ultraviolet star in the Scorpio constellation. Later, Giacconi and his collaborators discovered a background of X-ray radiation evenly distributed across the sky.

“Giacconi really can be considered the father of cosmic X-ray astronomy,” Hughes says.

Orbiting X-ray observatories have carried on highly productive studies (SN: 10/21/00, p. 266: http://www.sciencenews.org/20001021/bob1.asp), and Giacconi still uses data from the orbiting Chandra X-ray Observatory to study sources that make up the X-ray background.

“Cutting-edge technology has always been a part of research in X-ray astronomy,” Hughes notes. “Riccardo made sure his group . . . was at the forefront of developments concerning X-ray telescopes and detectors, spacecraft, data analysis and interpretation.”

Chemistry

This year’s Nobel Prize in Chemistry, announced as Science News was going to press, recognizes the development of analytical tools for studying large biological molecules, such as proteins. The tools have transformed pharmaceutical development by enabling quick determinations of the identities and three-dimensional structures of molecules central to countless biological processes.

John B. Fenn of Virginia Commonwealth University in Richmond shares half of the prize with Koichi Tanaka of the Shimadzu Corp. in Kyoto, Japan. The other half goes to Kurt Wüthrich of the Swiss Federal Institute of Technology in Zurich and the Scripps Research Institute in La Jolla, Calif. Look for more on their research in next week’s Science News.

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