Susumu Tonegawa, who made fundamental contributions to the discovery of the genetic basis of antibody diversity, has passed away at 86.
Tonegawa was born in Japan and educated at Kyoto University, where he fell in love with molecular biology. He moved to the U.S. to pursue doctoral studies at the University of California, San Diego, and in 1968 took up a postdoctoral fellow position in the lab of Lasker laureate Renato Dulbecco at the Salk Institute. In the early 1970s, Tonegawa moved to the Basel Institute of Technology, where he became fascinated with the question of antibody diversity.
At the time, it was known that the human immune system could produce a vast array of different antibodies, each of which can bind to a particular antigen. (It is now known that the immune system can produce billions of distinct antibodies). The mapping of the human genome was decades away—but could it be the case that a unique gene was required to produce each unique antibody? This was the question that Tonegawa pursued.
In a series of elegant studies, Tonegawa demonstrated that the DNA responsible for antibody production is routinely reshuffled to create new genes during the lifetime of an individual. In 1987, Tonegawa (along with scientists Leroy Hood and Philip Leder, who worked independently on the question) was honored with a Lasker Basic Medical Research Award for detailing in molecular terms the genetics of antibody diversity.
Later in his career, Tonegawa changed his scientific focus to neuroscience. At the the Picower Institute for Learning and Memory at the Massachusetts Institute of Technology and at the RIKEN Brain Science Institute in Japan, Tonegawa worked on unraveling the molecular, cellular, and neural circuit mechanisms that underlie learning and memory.
