Hope for Coral Reefs
Global warming is expected to devastate coral reefs worldwide—but scientists have taken a step toward identifying the genetic mechanisms that give some corals a natural resilience to thermal stress. Coral reef ecologist Daniel Barshis and colleagues at Stanford University in Palo Alto, California, collected samples of the thermally tolerant Acropora hyacinthus in reefs in two pools at Ofu Island, American Samoa; one pool had highly variable temperatures, topping 34°C in summer, whereas the other was more moderately variable. The team subjected the samples to laboratory thermal stress experiments while monitoring the activity of a range of genes.
The researchers identified 60 genes that were normally more active in the corals from the highly variable pool—but became more active in corals from the moderately variable pool when water temperatures rose. The higher gene expression under normal conditions—called "frontloading"—may prepare these resilient corals for periodic hot water, the team reported online this week in the Proceedings of the National Academy of Sciences. http://scim.ag/Ofureef
Drug Restores Hearing in Mice
A drug applied to the ears of mice deafened by ear-splitting noise can restore some hearing in the animals. The compound, which blocks the action of a key developmental protein called Notch, allows the sound-sensing inner ear cells damaged by the noise to regrow. Although birds and fish can regenerate these so-called hair cells, mammals can't do so. Because noise, antibiotics, and other insults can harm hair cells, researchers have looked for ways to reactivate that latent regenerative potential. In 2005, scientists used gene therapy to prompt the growth of hair cells in adult guinea pigs, which also restored some hearing. However, the drug approach would potentially be much simpler, says Albert Edge, a stem cell biologist at the Massachusetts Eye and Ear Infirmary in Boston. He and his colleagues describe their results with the drug, originally developed as a potential Alzheimer's treatment, in the 10 January issue of Neuron. It is not ready yet to try in humans, Edge says, "but it's a foot in the door."