Mice and lamprey fish produce a similar antibody response to influenza, despite being separated by hundreds of millions of years of evolution.

Credit: Paul van Hoof/natureinstock.co/ardea.com

Lampreys (pictured) are jawless fish whose common ancestor with mammals lived 550 million years ago. They defend themselves with antibodies that are unlike those produced by the immune systems of jawed vertebrates. A team led by Jonathan Yewdell at the National Institute of Allergy and Infectious Diseases in Bethesda, Maryland, exposed lamprey larvae to inactivated influenza virus and found that their blood cells produced antibodies that recognize key amino-acid sites on the head of the haemagglutinin protein of influenza. This is the same region as that targeted by influenza antibodies from mice, suggesting that lamprey and mouse antibodies recognize pathogens in a similar way despite their huge evolutionary separation.

eLife 4, e07467 (2015)