| Project/Area Number |
13460002
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Breeding science
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| Research Institution | Meijo University (2002-2003)
The University of Tokyo (2001) |
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Principal Investigator |
HIRAI Atsushi Meijo Univ., Fac. Agric., Professor, 農学部, 教授 (60023470)
|
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| Co-Investigator(Kenkyū-buntansha) |
KADOWAKI Kohichi Natl.Inst.Agrobio.Res., Head of Team, チーム長
中園 幹生 東京大学, 大学院・農学生命科学研究科, 助手 (70282697)
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| Project Period (FY) |
2001 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥15,400,000 (Direct Cost: ¥15,400,000)
Fiscal Year 2003: ¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2002: ¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2001: ¥7,900,000 (Direct Cost: ¥7,900,000)
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| Keywords | complete sequence / gene expression / mitochondria genome / rice / 全塩基配列 / ミトコンドリア / 遺伝情報 / 塩基配列 |
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| Research Abstract |
The entire mitochondrial genome of rice (Oryza saliva L.), a monocot plant, has been sequenced. It was found to comprise 490,520 bp, with an average G+C content of43.8%. Three rRNA genes, 17 tRNA genes and five pseudo tRNA sequences were identified. In addition, eleven ribosomal protein genes and two pseudo ribosomal protein genes were found, which are homologous to 13 of the 16 genes for ribosomal proteins in the mitochondrial genome of the liverwort (Marchantia polymorpha). A greater degree of variation in terms of presence/absence and integrity of genes was observed among the ribosomal protein genes and tRNA genes, of rice, Arabidopsis and sugar beet. Transcription and post-transcriptional modification (RNA editing) in the rice mitochondrial sequence were also examined. In all, 491 Cs in the genomic DNA were converted to Ts in cDNA. The frequency of RNA editing differed markedly depending upon the ORF considered. Sequences derived from plastid and nuclear genomes make up 6.3% and 13.4% of the mitochondrial genome, respectively. The degree of conservation of plastid sequences in the mitochondrial genome ranged from 61% to 100%, suggesting that sequence migration has occurred very frequently. Three plastid DNA fragments that were incorporated into the mitochondrial genome were subsequently transferred to the nuclear genome. Nineteen fragments that were similar to transposon or retrotransposon sequences, but different from those found in the mitochondrial genomes of dicots, were identified. The results indicate frequent and independent DNA sequence flow to and from the mitochondrial genome during the evolution of flowering plants, and this may account for the range of genetic variation observed between the mitochondrial genomes of higher plants.
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