Susumu Ohno

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Susumu Ohno ( Japanese 大野 乾 , Ōno Susumu ; born February 1, 1928 in Keijō , Protectorate of Korea , Japanese Empire (now Seoul , South Korea ); † January 13, 2000 ) was a Japanese-American molecular biologist. He is best known for coining the term junk DNA in the 1960s and was concerned with molecular evolution and sex chromosomes .

Life

Ohno was born in Korea to Japanese parents. His father was Minister of Education there under the Japanese annexation of Korea, his maternal grandfather was a Supreme Court judge in Korea, and his paternal grandfather was a Chinese scholar. Since his father traveled a lot, Ohno grew up partly in Korea and partly in Japan. In 1945 the family went back to Japan. Ohno had been interested in horses since his youth (his father used both horse and car to get to the office) and studied veterinary medicine at the Tokyo University of Agriculture and Technology , where he received his PhD in 1949. He then continued his studies in genetics at the University of Hokkaidō and received his doctorate in 1953 with a dissertation on immunology. After that he went to the United States as a visiting scholar at the University of California, Los Angeles , where he Riojun Kinosita worked, which was known when he butter yellow as a carcinogen identified. Ohno followed Kinosita to the City of Hope National Medical Center in Duarte, California , where he stayed for the remainder of his career.

plant

In the 1950s he made important discoveries regarding sex chromosomes. In particular, he found that one of the two X chromosomes in women is shut down by heterochromatin ( Barr bodies ).

Ohno advocated the hypothesis that evolution at the gene level mainly took place via gene duplication (with neofunctionalization, that is, one of the copies when the gene is duplicated takes on a different function). He called a part of the DNA that was functionless junk DNA and he discovered that a large part of the DNA in higher living beings did not code. However, he also found relatively early on that the gene duplication mechanism no longer worked in mammals: their overall genetic material was almost constant, although they could clearly differ in the number of chromosomes (even in species that were close together). In 1970 he proposed the 2R hypothesis that vertebrates only went through two rounds of gene duplication in their initial development.

A law named after him expresses the approximate preservation of female X chromosomes in the course of the evolution of mammals.

In the mid-1980s he began to study the early origins of life. He found that under natural conditions in the primordial soup, DNA sequences could only be formed up to decamers, which was insufficient for the development of life. Instead, he suggested that pentamers formed predominantly and formed longer chains through hybridization . He also looked for a common gene blueprint at the stage of the Cambrian explosion .

Honors and memberships

Ohno was a member of the National Academy of Sciences (1981) and the American Academy of Arts and Sciences (1977). In 1992 he became a member of the Royal Danish Academy of Sciences . In 1981 he received the Japanese Society of Human Genetics Prize and the Francis Amory Prize of the American Academy of Arts and Sciences, the Kihara Prize of the Japanese Society of Genetics in 1983 and the Queen Margarethe Prize of the Danish Academy of Sciences in 1998. He was an honorary doctor of the University of Pennsylvania and his alma mater, the University of Agriculture and Technology in Tokyo. In 1999 he and his wife were received by the Japanese imperial couple on a visit to Japan.

Private

In 1951 he married Midori Aoyama (who could not follow him to the USA until 1953) and had two sons and a daughter. He was a US citizen. Ohno kept his lifelong interest in horses and kept and trained them.

With his wife he not only had the hobby horses, but also music. He even transcribed DNA sequences in musical form, performed by his wife as a singer.

Fonts

  • Sex Chromosomes and Sex-Linked Genes, Springer 1967
  • Evolution by gene duplication, Springer 1970
  • Major Sex-Determining Genes, Springer 1979

Web links

References and comments

  1. ↑ Ohno, WD Kaplan, R. Kinosita, Formation of Sex-Chromatin by a single X-chromosome in the liver cells of Rattus norvegicus, Exp. Cell Research, Volume 18, 1959, pp. 415-418
  2. ↑ Ohno, Evolution from primordial oligomeric repeats to modern coding sequences. J. Mol. Evol., Vol. 25, 1987, pp. 325-329
  3. ↑ Ohno, The notion of the Cambrian pananimalia genome. Proc. Natl. Acad. Sci. USA 93, 1998, pp. 8475-8478
personal data
SURNAME Ohno, Susumu
ALTERNATIVE NAMES Ōno Susumu; 大野 乾 (Japanese)
BRIEF DESCRIPTION Japanese-American molecular biologist
DATE OF BIRTH February 1, 1928
PLACE OF BIRTH Keijō , Protectorate of Korea (now Seoul, South Korea)
DATE OF DEATH January 13, 2000