Instead of becoming obese, mice with a mutation in an immune gene burn off the fat they eat. (p. 9)

Tasmanian devils all know each other, a new study shows. The discovery could mean that stopping the spread of an infectious cancer will be harder than previously thought.

New study finds calorie restriction delays age-related diseases in monkeys. Another study reports that an immune-suppressing drug helps elderly mice live longer. (p. 9)

A neural network active when the brain is at rest may prove critical to zoning out, a sense of self and envisioning the future. (p. 16)

A closer look at regeneration in axolotl amputees shows that tissue replacement relies on cellular “memory.” (p. 10)

Scientists in Japan have successfully introduced a foreign gene into a primate species for the first time, opening a new avenue for modeling human diseases, particularly brain disorders. (p. 13)

Detailed genetic analysis of the H1N1 swine flu virus indicates that its components have been present for years. The virus is still susceptible to drugs and vaccine development. (p. 12)