Genes & Cells

Virus gene makes caterpillars climb
Scientists have discovered a gene that baculoviruses use to hijack gypsy moth caterpillars’ brains. When infected with the virus, caterpillars climb to the tops of trees they live on, die, liquefy and rain down viruses on other gypsy moths. Now researchers at Pennsylvania State University in University Park and colleagues have discovered that a baculovirus gene called egt makes the caterpillars climb. Viruses lacking the gene still kill, but the caterpillars stay down at the base of the tree, the researchers report in the Sept. 9 Science. The egt gene produces an enzyme that inactivates one of the caterpillar’s molting hormones and leads to climbing. —Tina Hesman Saey

Endangered stem cells

Reprogrammed stem cells from two of the world’s most endangered animals may help bring the species back from the brink of extinction. Researchers at the Scripps Research Institute in La Jolla, Calif., the University of California, San Diego and the San Diego Zoo reprogrammed frozen skin cells taken from an endangered primate called a drill and from a northern white rhinoceros. The stem cells may one day be used to create eggs and sperm for breeding programs. It took many failures before the researchers succeeded in making stem cells from a male drill named Loon and a female rhino named Fatu. The accomplishment is reported online September 4 in Nature Methods.  —Tina Hesman Saey

Stomach bacteria break host’s DNA
A bacterium commonly linked with ulcers and stomach cancer can have a fatal touch. Helicobacter pylori breaks DNA inside host cells, researchers at the University of Zurich and the Technical University Munich report in the Sept. 6 Proceedings of the National Academy of Sciences. Host cells can usually repair the damage, but if the number of bacteria increase and cause more breakage or the cell’s repair machinery fails, the cell may die or turn cancerous. The breakage requires direct contact between the bacteria and host cells, but isn’t caused by bacterial proteins previously associated with ulcers and cancer. —Tina Hesman Saey

Good living turns white fat brown
Living well is not only the best revenge, it may help keep weight under control.  Researchers at Ohio State University found that mice in an environment packed with toys and companions turn energy-storing white fat into calorie-burning brown fat. Mice with plenty of physical and social stimulation turned on a protein called BDNF in a part of the brain called the hypothalamus. Increasing BDNF levels triggers white fat cells to transform into brown fat, the team reports in the Sept. 7 Cell Metabolism. The animal’s ability to stay lean even on a high fat diet comes from increased energy burning by brown fat rather than more exercise.  —Tina Hesman Saey