ANDRZEJ KRAUZEBats carry and transmit some of the world’s deadliest zoonotic viruses: Ebola, Marburg, Nipah, and the pathogen behind severe acute respiratory syndrome, SARS coronavirus, to name a few. What has puzzled researchers for a long time is why bats don’t appear to get sick from their unusually high microbial loads. The question has been nagging Peng Zhou, a virologist at China’s Wuhan Institute of Virology, for more than a decade, ever since he took part in a survey of bat populations in southern China. Zhou and his colleagues were looking for the strain of the SARS coronavirus responsible for the 2003 outbreak that sickened more than 8,000 people worldwide and killed nearly 800. “We started to think, why bats?” he says.
Other researchers have suggested that bats’ super-tolerance might have something to do with their ability to generate large repertoires of naïve antibodies, or that flight ramps up the animals’ body temperatures to a fever-like state that helps fight off infections. But in 2013, Zhou and his colleagues stumbled across another clue during a comparative genomics study of two distantly related bat species. The genes that showed some of the strongest evidence of positive selection, the team found, appeared to be related to DNA damage and innate immunity (Science, 339:456-60). “We thought we needed to go further and work on the molecular mechanics,” says Zhengli Shi, Zhou’s colleague at the Wuhan Institute and a coauthor on the study.
The team decided to focus on a protein ...
