|
Barbara McClintock (June 16, 1902 – September 2, 1992) was an American scientist and cytogeneticist who was awarded the 1983 Nobel Prize in Physiology or Medicine. McClintock received her PhD in botany from Cornell University in 1927. There she started her career as the leader in the development of maize cytogenetics, the focus of her research for the rest of her life. From the late 1920s, McClintock studied chromosomes and how they change during reproduction in maize. She developed the technique for visualizing maize chromosomes and used microscopic analysis to demonstrate many fundamental genetic ideas. One of those ideas was the notion of genetic recombination by crossing-over during meiosis—a mechanism by which chromosomes exchange information. She produced the first genetic map for maize, linking regions of the chromosome to physical traits. She demonstrated the role of the telomere and centromere, regions of the chromosome that are important in the conservation of genetic information. She was recognized among the best in the field, awarded prestigious fellowships, and elected a member of the National Academy of Sciences in 1944. During the 1940s and 1950s, McClintock discovered transposition and used it to demonstrate that genes are responsible for turning physical characteristics on and off. She developed theories to explain the suppression and expression of genetic information from one generation of maize plants to the next. Due to skepticism of her research and its implications, she stopped publishing her data in 1953. Later, she made an extensive study of the cytogenetics and ethnobotany of maize races from South America. McClintock's research became well understood in the 1960s and 1970s, as other scientists confirmed the mechanisms of genetic change and genetic regulation that she had demonstrated in her maize research in the 1940s and 1950s. Awards and recognition for her contributions to the field followed, including the Nobel Prize in Physiology or Medicine, awarded to her in 1983 for the discovery of genetic transposition; she is the only woman to receive an unshared Nobel Prize in that category. ==Early life== Barbara McClintock was born Eleanor McClintock on June 16, 1902 in Hartford, Connecticut, the third of four children born to physician Thomas Henry McClintock and Sara Handy McClintock. Thomas McClintock was the child of British immigrants, and Sara Handy, born Grace, descended from an old American ''Mayflower'' family. Marjorie, the oldest child, was born in October 1898; Mignon, the second daughter, was born in November 1900. The youngest, Malcolm Rider (called Tom), was born 18 months after Barbara. As a young girl, her parents determined that Eleanor, a "feminine" and "delicate" name, was not appropriate for her, and chose Barbara instead. McClintock was an independent child beginning at a very young age, a trait she later identified as her "capacity to be alone". From the age of three until she began school, McClintock lived with an aunt and uncle in Brooklyn, New York in order to reduce the financial burden on her parents while her father established his medical practice. She was described as a solitary and independent child, and a tomboy. She was close to her father, but had a difficult relationship with her mother, tension that began when she was young. The McClintock family moved to Brooklyn in 1908 and McClintock completed her secondary education there at Erasmus Hall High School; she graduated early in 1919. She discovered her love of science and reaffirmed her solitary personality during high school. She wanted to continue her studies at Cornell University's College of Agriculture. Her mother resisted sending McClintock to college, for fear that she would be unmarriageable. McClintock was almost prevented from starting college, but her father intervened just before registration began, and she matriculated at Cornell in 1919. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Barbara McClintock」の詳細全文を読む スポンサード リンク
|