Susumu Tonegawa (利根川進) (born September 6, 1939) is a Japanese scientist who won the Nobel Prize for Physiology or Medicine in 1987 for "his discovery of the genetic principle for generation of antibody diversity." Although he won the Nobel Prize for his work in immunology, Tonegawa is a molecular biologist by training. In his later years, he has turned his attention to the molecular and cellular basis of memory formation.

To achieve the diversity of anitbodies needed to protect against any type of antigen, the immune system would require millions of genes coding for different antibodies, if each antibody was encoded by one gene. Instead, as Tonegawa showed in a landmark series of experiments beginning in 1976, genetic material can rearrange itself to form the vast array of available antibodies. Comparing the DNA of B cells (a type of white blood cells) in embryonic and adult mice, he observed that genes in the B cells of the older mice are moved around, recombined, and deleted to form the diversity of the variable region of antibodies.

Tonegawa was born in Nagoya, Japan. He received his bachelor's degree from Kyoto University in 1963. He received his doctorate from the University of California, San Diego. He did post-doctoral work at the Salk Institute in San Diego, then worked at Basel Institute for Immunology in Basel, Switzerland where he performed his landmark immunology experiments. In 1981, he became a professor at the Massachusetts Institute of Technology.

External links

• Nobel Prize Biography
• Tonegawa's bio at MIT
• Tonegawa's research at the Center for Learning and Memory