Discovering the “on-and-off switch” for good parenting in both male and female mouse brains has earned Catherine Dulac, a molecular biologist at Harvard University, in Cambridge, Massachusetts, one of this year’s US$3-million Breakthrough prizes — the most lucrative awards in science and mathematics. Three other major prizes in biology, plus two in physics and one in mathematics, were also announced on 10 September, together with a number of smaller prizes.
“Catherine Dulac has done amazing work that has really transformed the field,” says biologist Lauren O’Connell, at Stanford University, California. Dulac’s team provided the first evidence that male and female mouse brains have the same neural circuitry associated with parenting, which is just triggered differently in each sex. “It went against the dogma that for decades said that male and female brains are organized differently,” says O’Connell.
Dulac says she was stunned to learn that she had won the award. “My brain froze, then I began to tear up,” she says, adding that it had been a long road to acceptance, because others had initially been sceptical of her work. In the 1990s, Dulac isolated the pheromone receptors in mice that govern sex-specific social behaviours. Virgin male mice usually attack other males and kill pups. But Dulac found that if their pheromone receptors were blocked, they would attempt to mate with both males and females, and virgin males would even care for pups. Pheromone-blind females, by contrast, would attempt to mount males.