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ULTRASTRUCTURAL STUDIES OF RADIATION-INDUCED CHROMOSOME DAMAGE
The fine structure of radiation-induced chromosomal aberrations in Potorous tridactylis (rat kangaroo) cells was examined in situ by electron microscopy. The observations on the structure of terminal deletions (acentric fragments), anaphase bridges and "gaps," sidearm bridges, and speciali...
Autores principales: | , |
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Formato: | Texto |
Lenguaje: | English |
Publicado: |
The Rockefeller University Press
1969
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2107714/ https://www.ncbi.nlm.nih.gov/pubmed/4895598 |
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author | Humphrey, Ronald M. Brinkley, B. R. |
author_facet | Humphrey, Ronald M. Brinkley, B. R. |
author_sort | Humphrey, Ronald M. |
collection | PubMed |
description | The fine structure of radiation-induced chromosomal aberrations in Potorous tridactylis (rat kangaroo) cells was examined in situ by electron microscopy. The observations on the structure of terminal deletions (acentric fragments), anaphase bridges and "gaps," sidearm bridges, and specialized regions, such as the nucleolus organizer, are discussed in detail. Conclusions based on these observations are the following: (a) damage is physically expressed only at anaphase; (b) a gap region is composed of two subunits, each of which is about 800–1000 A in diameter and may correspond to a half-chromatid structure; (c) the ends of acentric fragments are structurally similar to normal chromosome ends, except where the break occurs in a specific region such as the secondary constriction; (d) at metaphase the fragment and the main portion of the chromosome move as a single unit to the equator, and the two units are disconnected only at the onset of anaphase; (e) sidearm bridges appear to be exchanges, involving a subchromatid unit. The interpretation of this evidence is consistent with the hypothesis that the chromosome is a multistranded structure. |
format | Text |
id | pubmed-2107714 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 1969 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-21077142008-05-01 ULTRASTRUCTURAL STUDIES OF RADIATION-INDUCED CHROMOSOME DAMAGE Humphrey, Ronald M. Brinkley, B. R. J Cell Biol Article The fine structure of radiation-induced chromosomal aberrations in Potorous tridactylis (rat kangaroo) cells was examined in situ by electron microscopy. The observations on the structure of terminal deletions (acentric fragments), anaphase bridges and "gaps," sidearm bridges, and specialized regions, such as the nucleolus organizer, are discussed in detail. Conclusions based on these observations are the following: (a) damage is physically expressed only at anaphase; (b) a gap region is composed of two subunits, each of which is about 800–1000 A in diameter and may correspond to a half-chromatid structure; (c) the ends of acentric fragments are structurally similar to normal chromosome ends, except where the break occurs in a specific region such as the secondary constriction; (d) at metaphase the fragment and the main portion of the chromosome move as a single unit to the equator, and the two units are disconnected only at the onset of anaphase; (e) sidearm bridges appear to be exchanges, involving a subchromatid unit. The interpretation of this evidence is consistent with the hypothesis that the chromosome is a multistranded structure. The Rockefeller University Press 1969-09-01 /pmc/articles/PMC2107714/ /pubmed/4895598 Text en Copyright © 1969 by The Rockefeller University Press. This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/). |
spellingShingle | Article Humphrey, Ronald M. Brinkley, B. R. ULTRASTRUCTURAL STUDIES OF RADIATION-INDUCED CHROMOSOME DAMAGE |
title | ULTRASTRUCTURAL STUDIES OF RADIATION-INDUCED CHROMOSOME DAMAGE |
title_full | ULTRASTRUCTURAL STUDIES OF RADIATION-INDUCED CHROMOSOME DAMAGE |
title_fullStr | ULTRASTRUCTURAL STUDIES OF RADIATION-INDUCED CHROMOSOME DAMAGE |
title_full_unstemmed | ULTRASTRUCTURAL STUDIES OF RADIATION-INDUCED CHROMOSOME DAMAGE |
title_short | ULTRASTRUCTURAL STUDIES OF RADIATION-INDUCED CHROMOSOME DAMAGE |
title_sort | ultrastructural studies of radiation-induced chromosome damage |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2107714/ https://www.ncbi.nlm.nih.gov/pubmed/4895598 |
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