| Project/Area Number |
03454065
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
応用生物化学・栄養化学
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
OHYAMA Kanji Kyoto Univ., Faculty of Agriculture, Professor, 農学部, 教授 (40135546)
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| Project Period (FY) |
1991 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥6,200,000 (Direct Cost: ¥6,200,000)
Fiscal Year 1993: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1992: ¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1991: ¥2,700,000 (Direct Cost: ¥2,700,000)
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| Keywords | Marchantia polymorpha / Chloroplast genome / Nuclear genome / Plant cell / Organelle / Complete nucleotid sequence / Genetic information system / Mitochondrial genome |
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| Research Abstract |
Plant cell has two organelles, mitochondria and chloroplast, and they have their own DNA.To elucidate the genetic information systems of both organelles, we have already determined the complete nucleotide sequence of the liverwort chloroplast DNA and analyzed them. Plant mitochondria genomes are variable in size and more complex than mammalian and fungal mitochondrial genomes. These feature hamper the determination of the complete gene organization of the mitochondrial genomes of plant species. So, we have determined the complete sequence of the liverwort mitochondrial DNA and detected 96 possible gene in the sequence of 186,608 basepairs. These included genes for three species of ribosomal RNA, 29 genes for 27 species of transfer RNA and 31 open reading frames(ORFs) for functionally known proteins and 33 ORFs predicted as possible genes. We also found two pseudogenes. So far, 32 introns have been found in the coding regions of 17 genes. Even after allowing for wobbling and modification of the anticodons, two species of tRNA genes that are required for reading all codons in the liverwort mitochondrial genome have not been detected. They may be nulear-encoded and imported from the cytoplasm. RNA editing reported in mitochondrial genomes from several species of plants is apparently lacking in liverwort mitochondria. There were two major clusters of the ribosomal protein genes, in which the genes were arranged in a similar order to the E.coli operons. This observation strongly supports the endsymbiont hypothesis, which postulated that the organelles of eukaryotes originated from pokaryotic ancestors in evolution.
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