New research from the University of Pennsylvania is beginning to crack the code of which strain of flu will be prevalent in a given year, with major implications for global public health preparedness. The findings will be published on February 17 in the open-access journal PLoS Genetics.
Joshua Plotkin and Sergey Kryazhimskiy, both at the University of Pennsylvania, conducted the research with colleagues at McMaster University and the Institute for Information Transmission Problems of the Russian Academy of Sciences. Plotkin believes that his group’s computational study of 40 years of flu genomes offers a new way of looking at mutations: by cataloging pairs of genetic changes that have occurred in rapid succession, observing that a mutation in one half of the pair can act as an early warning sign of a mutation about to occur in the other.
Tracking single mutations in a vacuum is not always enough to understand how the flu virus evolves. “Sometimes a mutation is functional or adaptive only if it’s in the context of a certain genetic background – that is, if the protein already has some other mutation,” Plotkin said. The influence such combinations have on an organization’s adaptive fitness is known as epistasis.