| Project/Area Number |
59340043
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| Research Category |
Grant-in-Aid for Co-operative Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
植物形態・分類学
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| Research Institution | Hokkaido University |
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Principal Investigator |
IWABUCHI Masaki Hokkaido University; Fac. of Science Associate Professor, 理学部, 助教授 (30000839)
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| Co-Investigator(Kenkyū-buntansha) |
ITO Michio Nagoya University; Fac. of Science Associate Professor, 理学部, 助教授 (70022671)
FUKASAWA Hirosuke Kobe Women's University; Professor, 家政学部, 教授 (40030746)
MATSUMOTO Hideaki Okayama University; Associate Professor, 農業生物学研究所, 助教授 (80026418)
TANIFUJI Shigeyuki Hokkaido University; Fac. of Science Professor, 理学部, 教授 (50000774)
KUROIWA Tsunehiro Natl. Inst. Basic Biol.; Professor, 基礎生物学研究所, 教授 (50033353)
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| Project Period (FY) |
1984 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥11,900,000 (Direct Cost: ¥11,900,000)
Fiscal Year 1986: ¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1985: ¥4,700,000 (Direct Cost: ¥4,700,000)
Fiscal Year 1984: ¥4,700,000 (Direct Cost: ¥4,700,000)
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| Keywords | Chromatin structure / Gene transcription / DNA topoisomerase <II> / Repeated DNA sequence / DNA methylation / Organella chromosome / オルガネラ染色体 / DNA複製開始点 |
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| Research Abstract |
The object of the present co-operative research is to investigate the relationship between the gene expression and the structural changes of chromosomes in higher plants at the molecular and cellular levels. The results obtained here are as follows.
1. Research at the molecular level.
(1) The existence of the cis-and trnas-acting control elements for the transcription of wheat histone H3 and H4 genes was demonstrated in the in vivo transcription experiment with transformed sunflower cells by the Ti plasmid gene transfer method. (2) The in vivo reconstitution experiments with cauliflower chromatin showed that DNA topoisomerase <II> is involved in the process of the construction of chromosomes. (3) Two kinds of the highly repeated DNA sequences in the Vicia faba nuclear genome were supposed to be one of the major constituents of heterochromatin. (4) It was demonstrated in the in vitro experiments with isolated pea chromatin that calcium ions affect the structure and template activity of chromatin.
2. Research at the cellular level.
(1) The differences in the shape of chromosomes at the interphase and the DNA replication pattern resulted in the morphological differences of the metaphase chromosomes in the orchis somatic cells. Similar results were obtained with meiotic chromosomes in the pollen mother cells of Trillium and Lillium. (2) The DNA methylation was connected with the structural changes of chromosomes, such as the condensation or the dispersion of chromatin, in the pollen grain cells.
3. Research of organella chromosomes.
(1) It was clarified that the chromosomes of higher plant mitochondria form the DNA- protein complex but do not exist as free DNA. (2) The DNA replication origin of the cauliflower mitochondria DNA was estimated by the electron-microscopic observation of DNA.
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