FINE-STRUCTURE OF INTERPHASE NUCLEI .6. INITIATION AND REPLICATION SITES OF DNA-SYNTHESIS IN NUCLEI OF PHYSARUM-POLYCEPHALUM AS REVEALED BY ELECTRON-MICROSCOPIC AUTORADIOGRAPHY
FINE-STRUCTURE OF INTERPHASE NUCLEI .6. INITIATION AND REPLICATION SITES OF DNA-SYNTHESIS IN NUCLEI OF PHYSARUM-POLYCEPHALUM AS REVEALED BY ELECTRON-MICROSCOPIC AUTORADIOGRAPHY
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DOI：
10.1007/bf00291023
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发表时间：
1973-01-01
期刊：
影响因子：
1.6
通讯作者：
KUROIWA, T
中科院分区：
文献类型：
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作者：
KUROIWA, T
用电镜放射自显影技术研究了多头绒泡菌（Physarumpolycephalum）原质团核DNA合成的起始和复制位点。通过使用薄切片和整体封片技术，表明细胞核中的致密染色质团主要由直径约300 μ m的基本染色质样原纤维组成，而细胞核中的电子透明区主要由直径小于100 μ m的较细原纤维组成。用电镜放射自显影法发现：（1）DNA合成的起始位点肯定在致密染色质团与电子透明区的交界处;（2）DNA合成的起始和复制位点肯定不在核膜上;（3）在几分钟内，复制位点从起始位点迁移到电子透明区;（4）在电子透明区，几乎所有的核DNA都被合成。
The initiation and replication sites of DNA synthesis in the plasmodial nuclei ofPhysarum polycephalumwere studied with electron microscopic autoradiography. By using both thin sectioning and whole mount techniques, it was shown that the dense chromatin masses in the nucleus consisted of predominantly elementary chromatin-like fibrils, approximately 300 Å in diameter while the electron transparent region in the nucleus consisted of predominantly finer fibrils, less than 100 Å in diameter. With electron microscopic autoradiography it was found that (1) the initiation sites of DNA synthesis were definitely in the boundary regions between the dense chromatin masses and the electron transparent region, (2) the initiation and replication sites of DNA synthesis were definitely not on the nuclear membrane, (3) within a few minutes, replication sites migrated from the initiation sites to the electron transparent region and (4) in this electron transparent region, almost all of the nuclear DNA was synthesized.