Project/Area Number |
63540510
|
Research Category |
Grant-in-Aid for General Scientific Research (C)
|
Allocation Type | Single-year Grants |
Research Field |
遺伝学
|
Research Institution | National Institute of Genetics |
Principal Investigator |
GOJOBORI Takashi National Institute of Genetics, Assoc. Prof., 集団遺伝研究系, 助教授 (50162136)
|
Co-Investigator(Kenkyū-buntansha) |
MORIYAMA Etsuko National Institute of Genetics, Res. Asso., 集団遺伝研究系, 助手 (20210198)
HORAI Satoshi National Institute of Genetics, Res. Asso., 総合遺伝研究系, 助手 (40126157)
|
Project Period (FY) |
1988 – 1989
|
Project Status |
Completed (Fiscal Year 1989)
|
Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1989: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1988: ¥1,200,000 (Direct Cost: ¥1,200,000)
|
Keywords | RNA viruses / molecular evolution / nucleotide substitution / retroviruses / HTLV-I / II / AIDS viruses / HBV / ミトコンドリア遺伝子 / ヒトの進化 |
Research Abstract |
The aim of this research project was to clarify the evolutionary features of RNA viruses from the viewpoint of molecular evolution. In particular, we studied the rate of nucleotide substitutions of RNA viruses such as human immunodeficiency viruses (HIV) and oncoviruses. We found that the substitution rates of these typical retroviruses are the order of 10^<-3> per site per year. These rates are 10^6 times greater than those of eukaryotic genes including nuclear and mitochondrial genes. Although human hepatitis B virus (HBV) is not a RNA virus, we also examined the rate of nucleotide substitution of HBV. This is because HBV possesses reverse transcriptase that is a polymerase unique to retroviruses. The substitution rate of HBV is estimated to be the order of 10^<-5> per site per year. In the case of human T cell leukemia viruses types I and II (HTLV - I / II), we suggested that the substitution rate is much higher than those of eukaryotic genes but lower than those of retroviruses. Using the numbers of nucleotide substitutions, we constructed the phylogenetic trees for the above-mentioned viruses. As the result, we concluded that the viruses examined in this research show "host-independent evolution."
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