Susumu Ohno
Encyclopedia
was an Asian American geneticist
and evolutionary biologist, and seminal researcher in the field of molecular evolution
.
, Korea
, on February 1, 1928. The second of five children, he was the son of the minister of education of the Japanese Viceroyship of Korea
. The family returned to Japan after the war in 1945. He later became a citizen of the United States of America. Susumu Ohno married Midori Aoyama in 1951. They had two sons and one daughter.
His passion for science derived from his life-long love of horses. He earned a Ph.D. in veterinary science at Tokyo University of Agriculture and Technology
in 1949, and later a Ph.D. and D.Sc. from Hokkaido University. He went to the United States in 1951, as a visiting scholar to UCLA, and in 1952 joined the new research department at City of Hope Medical Center, where he remained in active research until 1996.
plays a major role in evolution in his classic book Evolution by Gene Duplication (1970). While subsequent research has overwhelmingly confirmed the key role of gene duplication in molecular evolution
, research to evaluate Ohno's model for the preservation of duplicate genes (now termed neofunctionalization) is ongoing and very active. He also discovered in 1956 that the Barr body
of mammalian female nuclei was in fact a condensed X chromosome. In Evolution by Gene Duplication, he also suggested that vertebrate
genome is the result of one or more entire genome duplications; variations of this idea have come to be known as the 2R hypothesis
(also called "Ohno's hypothesis"). He indicated that mammalian X chromosomes are conserved among species; it has been referred to as Ohno's law
.
Geneticist
A geneticist is a biologist who studies genetics, the science of genes, heredity, and variation of organisms. A geneticist can be employed as a researcher or lecturer. Some geneticists perform experiments and analyze data to interpret the inheritance of skills. A geneticist is also a Consultant or...
and evolutionary biologist, and seminal researcher in the field of molecular evolution
Molecular evolution
Molecular evolution is in part a process of evolution at the scale of DNA, RNA, and proteins. Molecular evolution emerged as a scientific field in the 1960s as researchers from molecular biology, evolutionary biology and population genetics sought to understand recent discoveries on the structure...
.
Biography
Susumu Ohno was born of Japanese parents in SeoulSeoul
Seoul , officially the Seoul Special City, is the capital and largest metropolis of South Korea. A megacity with a population of over 10 million, it is the largest city proper in the OECD developed world...
, Korea
Korea
Korea ) is an East Asian geographic region that is currently divided into two separate sovereign states — North Korea and South Korea. Located on the Korean Peninsula, Korea is bordered by the People's Republic of China to the northwest, Russia to the northeast, and is separated from Japan to the...
, on February 1, 1928. The second of five children, he was the son of the minister of education of the Japanese Viceroyship of Korea
Korea under Japanese rule
Korea was under Japanese rule as part of Japan's 35-year imperialist expansion . Japanese rule ended in 1945 shortly after the Japanese defeat in World War II....
. The family returned to Japan after the war in 1945. He later became a citizen of the United States of America. Susumu Ohno married Midori Aoyama in 1951. They had two sons and one daughter.
His passion for science derived from his life-long love of horses. He earned a Ph.D. in veterinary science at Tokyo University of Agriculture and Technology
Tokyo University of Agriculture and Technology
Established in 1949 as a national university, , nicknamed "Nōkōdai" or "TUAT", is a research-oriented national university with two campuses, one each located in the cities of Fuchū and Koganei, Tokyo....
in 1949, and later a Ph.D. and D.Sc. from Hokkaido University. He went to the United States in 1951, as a visiting scholar to UCLA, and in 1952 joined the new research department at City of Hope Medical Center, where he remained in active research until 1996.
Scientific contributions
Ohno postulated that gene duplicationGene duplication
Gene duplication is any duplication of a region of DNA that contains a gene; it may occur as an error in homologous recombination, a retrotransposition event, or duplication of an entire chromosome.The second copy of the gene is often free from selective pressure — that is, mutations of it have no...
plays a major role in evolution in his classic book Evolution by Gene Duplication (1970). While subsequent research has overwhelmingly confirmed the key role of gene duplication in molecular evolution
Molecular evolution
Molecular evolution is in part a process of evolution at the scale of DNA, RNA, and proteins. Molecular evolution emerged as a scientific field in the 1960s as researchers from molecular biology, evolutionary biology and population genetics sought to understand recent discoveries on the structure...
, research to evaluate Ohno's model for the preservation of duplicate genes (now termed neofunctionalization) is ongoing and very active. He also discovered in 1956 that the Barr body
Barr body
A Barr body is the inactive X chromosome in a female somatic cell, rendered inactive in a process called lyonization, in those species in which sex is determined by the presence of the Y or W chromosome rather than the diploidy of the X or Z...
of mammalian female nuclei was in fact a condensed X chromosome. In Evolution by Gene Duplication, he also suggested that vertebrate
Vertebrate
Vertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds...
genome is the result of one or more entire genome duplications; variations of this idea have come to be known as the 2R hypothesis
2R hypothesis
The 2R hypothesis or Ohno's hypothesis, first proposed by Susumu Ohno in 1970, is a contested hypothesis in genomics and molecular evolution suggesting that the genomes of the early vertebrate lineage underwent one or more complete genome duplications, and thus modern vertebrate genomes reflect...
(also called "Ohno's hypothesis"). He indicated that mammalian X chromosomes are conserved among species; it has been referred to as Ohno's law
Ohno's law
Ohno's law was proposed by a Japanese biologist Susumu Ohno, saying that the gene content of the mammalian species has been conserved over species not only in the DNA content but also in the genes themselves...
.