Susumu Tonegawa

Susumu Tonegawa (利根川 進 Tonegawa Susumu, 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.

Tonegawa is best known for elucidating the genetic mechanism in the adaptive immune system. To achieve the diversity of antibodies 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 cell) in embryonic and adult mice, he observed that genes in the mature B cells of the adult mice are moved around, recombined, and deleted to form the diversity of the variable region of antibodies.

Tonegawa was born in Nagoya, Japan and attended the Hibiya High School in Tokyo. . 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 in the laboratory of Renato Dulbecco, then worked at the 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, and founded and directed the Picower Institute for Learning and Memory at MIT.In 1982, he was awarded the Louisa Gross Horwitz Prize from Columbia University together with Barbara McClintock another nobel prize winner in 1983.

In 2006, Tonegawa was accused of discouraging the recruitment of a female junior faculty candidate in the McGovern Institute for Brain Research, another MIT neuroscience unit, by informing her that they would likely become competitors at MIT. In a letter to MIT President Susan Hockfield, 11 tenured female MIT professors requested an investigation of potentially unethical conduct. An investigation by an internal MIT committee submitted a report to the Provost, who with the President wrote letters to the MIT community. The committee found no evidence of gender bias. On November 17, 2006, Tonegawa announced his resignation as director of the Picower Institute for Learning and Memory, effective December 31, 2006.