IMMUNOLOGY: Regulatory T Cells Tactful in Controlling Killer Cousins
Usually only the budding T cells that have learned to refrain from attacking the body’s own tissues become mature T cells. Still, self-reactive T cells occasionally escape. Thirty years ago, a pair of researchers proposed that these renegade cells are intercepted and subdued by a population of suppressor cells. The whole concept of a suppressor cell fell into disrepute, however, until the mid-1990s when a researcher identified a CD25-bearing T cell that stopped self-reactive T cells from turning on the body. Ulrich von Andrian and colleagues now have observed—and captured on video—individual cytotoxic T cells mounting an attack, which regulatory T cells indirectly halt. The team reports its findings in the July 29 Immunity.

GENETICS: Gene Linked to Beak Length in Darwin Finch
Call it the Pinocchio gene. Led by Arkhat Abzhanov (left), researchers in the lab of Clifford Tabin have discovered a molecular pathway that lengthens the beaks of Darwin’s finches while they develop in the egg. Built sturdy and stout for cracking nuts or long and tapering for sipping cactus nectar, the beak and its diversity among the closely related finches of the Galapagos Islands may be the most famous living example of Darwin’s theories of evolution and natural selection. The latest finding, in the Aug. 3 Nature, comes two years after the discovery of a gene that sculpts beak height and width.

MOLECULAR MEDICINE: Light Shone on Disease-fighting Effect of Omega-3s
Recently, research on the effects of omega-3s has begun to bring them into the realm of molecular medicine. Two years ago, Jing Kang revealed a transgenic mouse engineered to convert omega-6 fatty acids into omega-3s. These mice generated a great deal of interest as a tool for studying the effect of changing the ratio of essential fats in the diet—something that has been hypothesized to be important for health. Since then, Kang’s group as well as several other laboratories have begun to use the mice to study a variety of diseases. Kang’s lab recently published two papers in Proceedings of the National Academy of Sciences showing that higher levels of omega-3 fatty acids protect mice from colitis and slow melanoma growth.