利用者:Norihiro Okada

Norihiro Okada
生誕	(1947-10-17) 1947年10月17日 日本 Tokyo
居住	日本
国籍	日本
研究分野	Molecular Biology
研究機関	Tokyo University National Cancer Center Research Institute NIH USA Tsukuba University Tokyo Institute of Technology
出身校	Tokyo University
博士課程 指導教員	Susumu Nishimura
主な業績	retrotransposon method for phylogenetic determination invented
主な受賞歴	purple ribbon
プロジェクト:人物伝

Norihiro Okada（194717 Oct - ）is an evolutionary biologist and molecular biologist in Japan. A new method for determining phylogenetic relationships, the so-called retroposon method, was devised and used to prove that whales and hippopots are closely related. After retiring from the graduate school of the Tokyo Institute of Technology, he served as professor at the National Cheng Kung University (Taiwan), principal investigator of the Foundation of Advancement of International Science (FAIS) as director of the Coelacanth Institute. He is currently professor at Kitasato University, visiting professor at Nagahama Institute of Bio-Science and Technology, and professor emeritus at the Tokyo Institute of Technology.

== History/Person==

Born in Tokyo. After entering Kaisei junior high and senior high schools, he entered science class II at the University of Tokyo in 1967. He was enthusiastic about drama in his undergraduate days. Graduated in 1973 from the Faculty of Agriculture, Department of Agriculture and Chemistry. In 1975, he completed his master's course at the University of Tokyo, Graduate School of Pharmaceutical Sciences. He graduated from the Graduate School of Pharmaceutical Sciences in the University in 1978, and got a doctor of pharmacy. In the same year, he worked as a post-doctoral fellow in NIH USA. Professor, Department of Biological Sciences, University of Tsukuba, 1979. He was an assistant professor in 1988. Since 1992, he had been a professor at the Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology. Since 2000, he had been a professor at the Graduate School of Bioscience and Biotechnology. Retirement at the mandatory retirement age in 2013. In 2012, he was appointed as a Professor in the National Cheng Kung University (NCKU) (Taiwan)and started a fighting fish project trying to elucidate what happened in brains of fish when they fight by using the RNA-seq method. Research on Japanese medicine began in 2017 as a principal investigator in FAIS. Since April 2020, as a project professor at Kitasato University, he has been working on "preemptive medicine from the viewpoint of molecular biology."

He discovered that a type of retroposon, the short interspersed element, abbreviated as SINE, has evolved from a tRNA (transfer RNA) in his mid-thirties in the Tsukuba University. Originally a molecular biologist, he has been interested in molecular evolution since then. By devising a retroposon method (SINE method), taking advantage of the property that once SINE is inserted into the genome, it does not return to the genome, he determined many phylogenetic relationships that had not been determined in the past. The demonstration of the close relationship between whales and hippopotamuses is well known (refs. 25 and 26). Most mammalian lineages have been elucidated by using this method (e.g., equine and bat relatives, 16). Other studies include the elucidation of salmon lineage, tooth whale (ref. 23) and beard whale lineage, turtle lineage, and aquatic bird lineage (ref. 2). Recently, his group demonstrated that the ancestral lineages of three placental mammals, namely Boreotheria (derived from Eurasia), Afrotheria (derived from Africa) and Xenarthra (derived from South America) diverged almost simultaneously. In a joint study with a geologist, Prof. Shigenori Maruyama, he proposes the hypothesis that the divergence of three continents, Eurasia, Africa and South America may have diverged at the same time as these lineage divergences at 120 million years ago. This is the first case in which a new geological hypothesis was proposed on the basis of DNA information (ref. 10). The method of using retroposon for determination of phylogenetic relationships is critically different from that of estimation for phylogenetic relationships by comparing conventional sequences. The retroposon method is a novel method that does not require any statistical methods, and it has already been established worldwide to provide a reliable systematic relationship without mistakes (ref. 24), and is being cited in many evolutionary textbooks. Many phylogenetic relationships are being determined using this method in many laboratories around the world.

Okada and his colleagues pursued the amplification mechanism of SINEs and LINEs, whose outcomes are the basis for the development of this retroposon method. The 3' end of SINE was shown to have the same sequence as that of LINE. From this observation, this group proposed a model in which the 3' end of SINE is recognized by RT and that SINE is amplified by RT in a similar manner that the 3' end of LINE is recognized by RT and that LINE is amplified by RT. The model was actually proven in molecular biological method and published in Cell (ref. 21). Okada and colleagues also proposd a new model for the insertion mechanism of LINEs (refs. 4, 5, 8, 14).

Traditionally, retroposons have been thought to be junk DNA with no function, but Okada and his colleagues have found that SINEs exist in parts of conserved sequences (Conserved Non-coding Element; CNE) that do not encode anything in the genome, providing the world's first possibility that SINEs may be involved in macro-evolution (ref. 17). Further experiments demonstrated the involvement of SINE in mammalian brain formation (ref. 12) and developed a world-leading study on the evolutionary role of retroposons.

With an interest in the speciation mechanism of African cichlid fish, Okada dispatched a research team to Lake Victoria for six years from 2003 by the support of Grant-in-Aid for scientific Research on Priority Area under the title of “The molecular mechanism of macro-evolution” from Ministry of Education, Culture, Sports, Science and Technology. Finally, they compiled a booklet on samples of Lake Victoria Ciclid. Focusing on the importance of color recognition for the speciation of fish species, this group proposed for the first time “Speciation by the sensory drive” in collaboration with Seehausen’s group. This discovery was published in journal Nature as an article (ref. 11). Okada participated in the Genome Consortium of Cichlid Fish and contributed to the publication of the article about cichlid genomes published in journal Nature (ref. 3).

When Okada was a professor at the Tokyo Institute of Technology (TokyoTech), he was the first Japanese scientist that imported a coelacanth specimen into Japan since CITES (so-called Washington Convention) was issued. This was performed as a joint research project between the Tanzania Fisheries Research Institute (TAFIRI) and the Okada Laboratory in TokyoTech (November 2005). In 2007, the coelacanth specimen was dissected at the presence of Prince Akishinonomiya in Tokyo Institute of Technology on December 21, the commemorative day when a coelacanth was first discovered at the coast of South African Republic. The second coelacanth specimen was imported in October 2007, which was the largest in the world with a total length of 170 cm. This specimen was the first in the world to undergo whole-body plastination (a method for permanent preservation by replacing water in the body with plastic). Later, three specimens of coelacanth were imported into TokyoTech at the same time. Accordingly, the coelacanth collection at TokotTech was the world's largest collection including five adult fish, ten young fish, and six eggs. On October 5, 2009, a fish scholar, His Majesty the Emperor, was invited to Tokyo Tech for dissection performance of a coelacanth specimen with eggs. After reaching the mandatory retirement age (65 years old) of the TokyoTech, Okada became the principal investigator of FAIS (director of the Coelacanth Institute) and consequently transferred these coelacanth samples to FAIS for the purpose of continuing coelacanth research. In 2013, the sequencing of the coelacanth genome, which had been carried out under an all-Japan collaboration, was determined and published in Genome Res. (Ref. 6). From 2013 to 2017, he had served concurrently as a Research Professor of National Cheng Kung University (NCKU) in Taiwan and had begun studying fish fighting. He discovered that when two male fighters fight each other, their behavior and transcriptomes are also synchronized (Ref. 1). This phenomenon of transcriptome synchronization not only occurs in a struggle but also is a universal phenomenon observed when higher animals have an interaction as a pair such as empathy.

Okada Norihiro, October 17, 1947 - is a Japanese molecular evolutionary chemist and molecular biologist.

TABLE OF CONTENTS 1 History and personality 2 Major Awards and Honours 3 Books and papers 4 External link

Awards

• TORAY Prize for Science and Technology (2010)
• Medal with Purple Ribbon(2007)
• Kihara Prize of the Genetics Society of Japan (2006)
• Fujiwara Prize(2006)
• Kimura Prize of the Japanese Evolution Society (2003)
• Selection for a fellow of AAAS(The American Association for the Advancement of Science) (2001)
• Kihara Memorial Foundation Academic Award(1996)
• Okada’s scientific history was described in his book entitled “Adventure of a Scientist”（2017, Kubapro）

papers

1. Vu TD, Iwasaki Y, Shigenobu S, Maruko A, Oshima K, (15 coauthors), Okada N. Behavioral and brain-transcriptomic synchronization between the two opponents of a fighting pair of the fish Betta splendens. PLOS Genet. (2020) 16:e1008831. doi: 10.1371/journal.pgen.1008831
2. Kuramoto T, Nishihara H, Watanabe M, and Okada N. Determining the Position of Storks on the Phylogenetic Tree of Waterbirds by Retroposon Insertion Analysis. Genome Biology and Evolution, 7(12):3180–3189. doi:10.1093/gbe/evv213 (2015)
3. Brawand D, (63coauthers), Okada N, (11coauthers). The genomic substrate for adaptive radiation in African cichlid fish. Nature,doi:10.1038/nature13726 (2014)
4. Yamaguchi K, Kajikawa M, and Okada N. Integrated mechanism for the generation of the 5′ junctions of LINE inserts. Nucleic Acids Research, Dec 1,42 (21):13269-79. doi: 10.1093/nar/gku1067 (2014)
5. Hayashi Y, Kajikawa M, Matsumoto T, and Okada N. Mechanism by which a LINE protein recognizes its 3′ tail RNA. Nucleic Acids Research, Aug 20, doi: 10.1093/nar/gku753 (2014)
6. Nikaido M (27 coauthors) Okada,N. Coelacanth genomes reveal signatures for evolutionary transition from water to land. Genome Res. 1, October (2013)
7. Yoshida K, Terai Y, Mizoiri S, Aibara M, Nishihara H, Watanabe M, Kuroiwa A, Hirai H, Hirai Y, Matsuda Y, Okada N. B chromosomes have a functional effect on female sex determination in lake victoria cichlid fishes. PLoS Genet. 2011 Aug;7(8):e1002203. (2011)
8. Suzuki J, Yamaguchi K, Kajikawa M, Ichiyanagi K, Adachi N, Koyama H, Takeda S and Okada N. Genetic evidence that the non-homologous end-joining repair pathway is involved in LINE retrotransposition. PLoS Genetics. 5, e1000461 (2009)
9. Nishihara H, Maruyama S, Okada N. Retroposon analysis and recent geological data suggest near-simultaneous divergence of the three superorders of mammals. Proc Natl Acad Sci USA. Mar 31; 106(13):5235-40 (2009)
10. Nishihara H, Maruyama S, Okada N.Retroposon analysis and recent geological data suggest near-simultaneous divergence of the three superorders of mammals. Proc Natl Acad Sci USA. 106(13):5235-40(2009)
11. Seehausen O, Terai Y, Magalhaes I.S, Carleton K.L, Mrosso H.D.J, Miyagi R, Sluijs V.I, Schneider M.V, Maan M, Tachida H, Imai H, Okada N. Speciation through sensory drive in cichlid fish. Nature, 455(7213) 620-6 (2008)
12. Sasaki T, Nishihara H, Hirakawa M, Fujimura K, Tanaka M, Kokubo N, Kimura-Yoshida C, Matsuo I, Sumiyama K, Saitou N, Shimogori T, Okada N. Possible involvement of SINEs in mammalian-specific brain formation. Proc Natl Acad Sci USA. 105(11), 4220-5 (2008)
13. Piskurek O, Okada N. Poxviruses as possible vectors for horizontal transfer of retroposons from reptiles to mammals. Proc Natl Acad Sci USA. 104(29):12046-51 (2007)
14. Ichiyanagi K, Nakajima R, Kajikawa M, Okada N. Novel retrotransposon analysis reveals multiple mobility pathways dictated by hosts. Genome Res. Jan;17(1):33-41 (2007)
15. Terai Y, Seehausen O, Sasaki T, Takahashi K, Mizoiri S, Sugawara T, Sato T, Watanabe M, Konijnendijk N, Mrosso HD, Tachida H, Imai H, Shichida Y, Okada N. Divergent Selection on Opsins Drives Incipient Speciation in Lake Victoria Cichlids. PLoS Biol. 5;4(12):e433 (2006)
16. Nishihara H, Hasegawa M, Okada N. Pegasoferae, an unexpected mammalian clade revealed by tracking ancient retroposon insertions. Proc Natl Acad Sci USA. 103(26),　9929-9934 (2006)
17. Nishihara H, Smit AF, Okada N. Functional noncoding sequences derived from SINEs in the mammalian genome. Genome Res. 22 (2006)
18. Sugawara T, Terai Y, Imai H, Turner G F, Koblmuller S, Sturmbauer C, Shichida Y, and Okada N. Parallelism of amino acid changes at the RH1 affecting spectral sensitivity among deep-water cichlids from Lakes Tanganyika and Malawi. Proc. Natl. Acad. Sci. USA 102, 5448-5453 (2005)
19. Terai Y, Morikawa N, Kawakami K, and Okada N. The complexity of alternative splicing of hagoromo mRNA is increased in an explosively speciated lineage in East African cichlids. Proc. Natl. Acad. Sci. U S A. 28, 12798-12803 (2003)
20. Terai Y, Mayer W E, Klein J, Tichy H, and Okada N. The effect of selection on a long wavelength-sensitive (LWS) opsin gene of Lake Victoria cichlid fishes. Proc. Natl. Acad. Sci. USA. 99, 15501-15506 (2002)
21. Kajikawa M, and Okada N. LINEs Mobilize SINEs in the Eel through a Shared 3' Sequence. CELL 111, 433-444 (2002)
22. Ogiwara I, Miya M, Ohshima K, and Okada N. V-SINEs: a new superfamily of vertebrate SINEs that are widespread in vertebrate genomes and retain a strongly conserved segment within each repetitive unit. Genome Res. 12, 316-324 (2002)
23. Nikaido M, Matsuno F, Hamilton H, Brownell R L Jr., Cao Y, Ding W, Zuoyan Z, Shedlock A M, Fordyce R E, Hasegawa M, and Okada N. Retroposon analysis of major cetacean lineages: the monophyly of toothed whales and the paraphyly of river dolphins. Proc. Natl. Acad. Sci. USA. 98, 7384-7389 (2001)
24. Shedlock A M, and Okada N. SINE Insertions : Powerful Tools for Molecular Systematics. BioEssays. 22, 148-160 (2000)
25. Nikaido M, Rooney A P, and Okada N Phylogenetic relationships among cetartiodactyls based on insertions of short and long interspersed elements: Hippopomamuses are the closest extant relatives of whales. Proc. Natl. Acad. Sci. USA. 96, 10261-10266 (1999)
26. Shimamura M, Yasue H, Ohshima K, Abe H, Kato H, Kishiro T, Goto M, Munechika I, and Okada N. Molecular evidence that whales form a clade within even-toed ungulates. Nature. 388, 666-670 (1997)