Briefs

© AAAS; E. Pennisi, Science, 295: 1809–11, 2002Wolbachia pipientis is a biological eye opener. This intracellular bacterium that colonizes insects and filarial nematodes kills male hosts but thrives in females, sometimes even influencing sexual determination. The recent completion of the W. pipientis genome reveals another unique quality: A streamlined genome without the loss of mobile elements and junk DNA."This finding was an enormous surprise," says Jonathan Eisen, investigator at

These papers were selected from multiple disciplines from the Faculty of 1000, a Web-based literature awareness tool http://www.facultyof1000.com.N. Sato et al., "Maintenance of pluripotency in human and mouse embryonic stem cells through activation of Wnt signaling by a pharmacological GSK-3-specific inhibitor," Nat Med, 10:55–63, January 2004.Sato and colleagues argue that inhibition of glycogen synthase kinase-3 (GSK3), resulting in activation of the Wnt-signaling pathway, is sufficient

Courtesy of Eric Robert RussellRecent gene-expression findings may energize the search for a mechanism in bipolar disorder pathology. Chris-tine Konradi and collaborators, from McLean Hospital, Belmont, Mass., and Harvard Medical School, showed that of 43 genes downregulated in brain specimens from subjects with bipolar disorder, 18 encode mitochondrial proteins.1 These results bolster a hypothesis put forth almost four years ago by Tadafumi Kato, currently at the RIKEN Brain Research Institute

Sunbathers at the beach could soon be applying DNA for protection rather than the highest SPF. Researchers led by David Goukassian and Barbara Gilchrest at the Boston University School of Medicine found that topical application of oligonucleotides increases DNA-repair after extensive UV exposure, thus reducing incidence of skin cancer in mice.Goukassian's team applied thymidine dinucleotide (pTT) to hairless mice prone to skin cancer.1 The topical DNA treatment upregulated and activated p53, enh

© Eye of Science/Photo ResearchersWhen a yeast cell falls onto an apple in the spring, life is good. Plentiful food and good weather maintain growth and division. But the good times don't last forever. "When resources dwindle due to competition, it makes sense to kill the less fit cells," says Frank Madeo of the Institute for Physiological Chemistry in Tübingen, Germany.Madeo and colleagues have mimicked the apple scenario in cultures to show that old Saccharo myces cerevisiae cells vo

© 2004 AACRBacterially induced gut cancers may solidify the role of oxidative stress in tumorigenesis. Medical oncologist Fong-Fong Chu and colleagues at City of Hope's Beckman Research Institute, Duarte, Calif., found that mice missing the glutathione peroxi-dase genes Gpx1 and Gpx2 are more likely to get intestinal cancer if exposed to bacteria, including Helicobacter hepaticus.1Both genes protect organisms from oxidative stress, strengthening the belief, says Chu, that such stress can le

Courtesy of Lars FuggerParadoxically, a single MHC class II allele, HLA-DQ0602, confers susceptibility to narcolepsy but prevents development of type I diabetes. Clinical immunologist Lars Fugger and structural biologist Yvonne Jones, both at Oxford University, have compared the crystal structure of the allele with those of two similar MHC molecules that respectively predispose to type 1 diabetes and protect against narcolepsy.1 They have identified unique features of several pockets within the

These papers were selected from multiple disciplines from the Faculty of 1000, a Web-based literature awareness tool http://www.facultyof1000.com.B. Van den Berg et al., "X-ray structure of a protein-conducting channel," Nature, 427:36–44, Jan. 1, 2004.The first crystal structure of a protein translocation channel demonstrates the principle according to which proteins are funneled across membranes. The pore has an hourglass shape with a "plug" in the middle that probably swings out of the

Courtesy of Chrissa KioussiLike ants marching to an unspoken command, embryonic heart cells follow distinct orders for organ formation, according to a group at the Pasteur Institute. Although many cardiac regulator genes have been isolated, researchers do not understand the cellular mechanisms that form a four-chambered heart from a simple tube. To track dividing cells in an embryonic mouse heart, researchers in Margaret Buckingham's lab created a transgenic line harboring an inactivated reporte

Courtesy of Steve Scadding and Sandra AckerleyResearchers aren't sure whether chromosomes maintain their place in the nucleus through mitosis or get lost in the shuffle. Biochemist Wendy Bickmore says it's the latter. Last March, two German research teams reached opposite conclusions about the heritability of chromatin organization – where chromosomes are within the nucleus and in relation to each other.1 Now Bickmore and colleagues in the Medical Research Council's Human Genetics Unit, Ed

The copiousness of the Drosophila Down Syndrome cell adhesion molecule (Dscam), puzzles geneticists. Through alternative splicing, Dscam can produce 38,016 unique protein isoforms. Yet, no one has discerned a reason for such bounty. Andrew Chess and postdoc Guilherme Neves, at the Whitehead Institute for Biomedical Research, suggest that Dscam variants may serve as identity signatures to help individual neurons discern self from non-self.1In the study, microarray data revealed temporal and spati

Courtesy Sidarta RibeiroSleep, to the joy of nappers everywhere, appears to be a building time for memories. Researchers at the Duke University Medical Center successfully recorded the electric signature of individual neurons firing during the two types of sleep, slow-wave sleep and rapid eye movement (REM) sleep.The team, led by postdoc Sidarta Ribeiro, implanted microscale probes into rat forebrain to determine the firing patterns of individual neurons "resonating" with recently captured memor

James King-Holmes/Science Photo LibraryIn the world of life-extending therapies, a lobotomy doesn't sound like an attractive option, but for the nematode Caenorhabditis elegans, destruction of particular sensory neurons can extend, or reduce, lifespan by as much as 30%. Joy Alcedo and Cynthia Kenyon at the University of California, San Francisco, have used a laser to kill individual neurons; they suggest that what may be happening to modify the lifespan of worms may also be at play in higher org

These papers were selected from multiple disciplines from the Faculty of 1000, a Web-based literature awareness tool http://www.facultyof1000.com.Q.L. Ying et al., "BMP induction of Id proteins suppresses differentiation and sustains embryonic stem cell self-renewal in collaboration with STAT3," Cell, 115:281–92, Oct. 31, 2003.Embryonic stem (ES) cells can be derived and propagated in the presence of bone morphogenetic protein 4 (BMP4) and leukemia inhibitory factor (LIF) without serum or

Camel Antibodies Used to Fight TrypanosomesFigure 1Belgian scientists say that small antibodies taken from the dromedary may prove useful in treating tropical parasites such as the African trypanosome, which causes sleeping sickness. Penetrating the dense, variable-specific surface glycoproteins that coat the organism, such antibodies may be able to zero in on conserved oligosaccharides hidden beneath. Serge Muyl-dermans and colleagues at the University of Brussels demonstrated its use as a diag

Indifferent to textbook dogma, some researchers have long suspected that bacteria really do have sex. They merge their genomes, research suggests, possibly by whole-cell fusion. Investigators liken the phenomenon to egg fertilization and distinguish it from conjugation, in which bacteria pass along bits of genetic material. A decade ago, Jean-Pierre Gratia, now at the Pasteur Institute of Brussels, Belgium, reported that mixing two nonconjugating Escherichia coli strains produced cells with both

Five Researchers Receive King Faisal Prizes In Science And Medicine Two From France To Get Wolf Prize In Mathematics Herbert Walther, director of the Max Planck Institute for Quantum Optics in Munich, Germany, and a professor of physics at Munich University, and Steven Chu, chairman of the physics department at Stanford University, have been selected as recipients of the King Faisal International Prize for Science. Jean-Claude Chermann, director of the laboratory of retroviruses and

Roberto J. Poljak, a professor and head of the structural immunology laboratory at the Pasteur Institute in Paris since 1981, has taken a position as director of the Center for Advanced Research in Biotechnology (CARB) in Rockville, Md. Established in 1984, CARB is a research institute founded by the University of Maryland's Biotechnology Institute and the National Institute of Standards and Technology. Poljak is known for developing the first three-dimensional models of key antibodies and a

Henry Hurwitz, Jr., a physicist at General Electric Co. who pioneered the theory and design of nuclear power plants and most recently helped engineer the reactor for the Seawolf nuclear submarine, died April 14 in Schenectady, N.Y., at the age of 73. In 1955, a year after Fortune magazine named him as one of the top 10 scientists in U.S. industry, Hurwitz contributed to establishing the first atomic containment sphere for GE. The development advanced industry-wide safety protocols for enclosin

W. Paul Havens, Jr., a professor of medicine at Jefferson Medical College and a prominent researcher into viral hepatitis, died April 6 at his home in Haverford, Pa., at the age of 80. Havens began his medical career in 1932 as a graduate of Harvard Medical School, when the amount of clinical information available in the United States was, of course, not nearly as voluminous as it is today. During the time Havens served with the U.S. Army Medical Corps in World War II, little was known about