SYNTHETIC CAPACITIES OF CHROMOSOME FRAGMENTS CORRELATED WITH THEIR ABILITY TO MAINTAIN NUCLEOLAR MATERIAL
Open Access
- 1 October 1962
- journal article
- research article
- Published by Rockefeller University Press in The Journal of cell biology
- Vol. 15 (1), 121-130
- https://doi.org/10.1083/jcb.15.1.121
Abstract
Onion (Allium cepa) and bean (Vicia faba) root tip cells containing many micronuclei, derived from x-ray-induced chromosome fragments, were exposed to H3-thymidine and H3-cytidine to determine the ability of such fragments to undergo DNA and RNA synthesis. Only a few micronuclei in onion and many in bean roots synthesize nucleic acid simultaneously with their main nuclei. A few micronuclei labeled with H3-thymidine undergo mitotic chromosome condensation along with the main nuclei, while the unlabeled ones never do so. The onset of nucleic acid synthesis as well as mitosis in micronuclei appears to be under generalized cellular control. Although all chromosomes and chromosome fragments at telophase give a positive reaction for a silver stainable nucleolar fraction, in the subsequent interphase only some micronuclei, derived from such chromosome fragments, are found to maintain nucleoli; others lose them with time. Those micronuclei which maintain nucleoli, perhaps due to the presence of specific chromosomal regions, are also active in DNA and RNA synthesis. These results are compatible with the concept that nucleoli and associated chromosome regions play an important role in the primary biosynthetic processes of the cell.Keywords
This publication has 20 references indexed in Scilit:
- RNA mediation in DNA synthesis in HeLa cells studied with tritium labeled cytidine and thymidineExperimental Cell Research, 1961
- THE SITE OF RIBONUCLEIC ACID SYNTHESIS IN THE ISOLATES NUCLEUSProceedings of the National Academy of Sciences, 1961
- Asynchronous replication of deoxyribonucleic acid in root tip chromosomes of Tradescantia paludosaExperimental Cell Research, 1961
- NUCLEIC ACID AND PROTEIN METABOLISM DURING THE MITOTIC CYCLE IN VICIA FABA The Journal of cell biology, 1961
- [New research on desoxyribonucleic acids in cooled, then reheated, cultures of fibroblasts. Cytophotometric and histoautoradiographic studies. Cytoplasmic localization of DNA].1961
- Inhibition of nucleic acid synthesis caused by X-irradiation of the nucleolusProceedings of the Royal Society of London. B. Biological Sciences, 1960
- Asynchronous Duplication of Chromosomes in Cultured Cells of Chinese HamsterThe Journal of cell biology, 1960
- Basic Proteins of Plant Nuclei during Normal and Pathological Cell GrowthThe Journal of cell biology, 1959
- STUDIES OF RIBONUCLEIC ACID METABOLISM WITH TRITIUM-LABELED CYTIDINE1959
- INFLUENCE OF THE NUCLEOLUS ON MITOSIS AS REVEALED BY ULTRAVIOLET MICROBEAM IRRADIATIONProceedings of the National Academy of Sciences, 1958