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Functional Redundancy in the Maize Meiotic Kinetochore
Kinetochores can be thought of as having three major functions in chromosome segregation: (a) moving plateward at prometaphase; (b) participating in spindle checkpoint control; and (c) moving poleward at anaphase. Normally, kinetochores cooperate with opposed sister kinetochores (mitosis, meiosis II...
Autores principales: | , |
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Formato: | Texto |
Lenguaje: | English |
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The Rockefeller University Press
2000
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2189807/ https://www.ncbi.nlm.nih.gov/pubmed/11018059 |
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author | Yu, Hong-Guo Dawe, R. Kelly |
author_facet | Yu, Hong-Guo Dawe, R. Kelly |
author_sort | Yu, Hong-Guo |
collection | PubMed |
description | Kinetochores can be thought of as having three major functions in chromosome segregation: (a) moving plateward at prometaphase; (b) participating in spindle checkpoint control; and (c) moving poleward at anaphase. Normally, kinetochores cooperate with opposed sister kinetochores (mitosis, meiosis II) or paired homologous kinetochores (meiosis I) to carry out these functions. Here we exploit three- and four-dimensional light microscopy and the maize meiotic mutant absence of first division 1 (afd1) to investigate the properties of single kinetochores. As an outcome of premature sister kinetochore separation in afd1 meiocytes, all of the chromosomes at meiosis II carry single kinetochores. Approximately 60% of the single kinetochore chromosomes align at the spindle equator during prometaphase/metaphase II, whereas acentric fragments, also generated by afd1, fail to align at the equator. Immunocytochemistry suggests that the plateward movement occurs in part because the single kinetochores separate into half kinetochore units. Single kinetochores stain positive for spindle checkpoint proteins during prometaphase, but lose their staining as tension is applied to the half kinetochores. At anaphase, ∼6% of the kinetochores develop stable interactions with microtubules (kinetochore fibers) from both spindle poles. Our data indicate that maize meiotic kinetochores are plastic, redundant structures that can carry out each of their major functions in duplicate. |
format | Text |
id | pubmed-2189807 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2000 |
publisher | The Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-21898072008-05-01 Functional Redundancy in the Maize Meiotic Kinetochore Yu, Hong-Guo Dawe, R. Kelly J Cell Biol Original Article Kinetochores can be thought of as having three major functions in chromosome segregation: (a) moving plateward at prometaphase; (b) participating in spindle checkpoint control; and (c) moving poleward at anaphase. Normally, kinetochores cooperate with opposed sister kinetochores (mitosis, meiosis II) or paired homologous kinetochores (meiosis I) to carry out these functions. Here we exploit three- and four-dimensional light microscopy and the maize meiotic mutant absence of first division 1 (afd1) to investigate the properties of single kinetochores. As an outcome of premature sister kinetochore separation in afd1 meiocytes, all of the chromosomes at meiosis II carry single kinetochores. Approximately 60% of the single kinetochore chromosomes align at the spindle equator during prometaphase/metaphase II, whereas acentric fragments, also generated by afd1, fail to align at the equator. Immunocytochemistry suggests that the plateward movement occurs in part because the single kinetochores separate into half kinetochore units. Single kinetochores stain positive for spindle checkpoint proteins during prometaphase, but lose their staining as tension is applied to the half kinetochores. At anaphase, ∼6% of the kinetochores develop stable interactions with microtubules (kinetochore fibers) from both spindle poles. Our data indicate that maize meiotic kinetochores are plastic, redundant structures that can carry out each of their major functions in duplicate. The Rockefeller University Press 2000-10-02 /pmc/articles/PMC2189807/ /pubmed/11018059 Text en © 2000 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 | Original Article Yu, Hong-Guo Dawe, R. Kelly Functional Redundancy in the Maize Meiotic Kinetochore |
title | Functional Redundancy in the Maize Meiotic Kinetochore |
title_full | Functional Redundancy in the Maize Meiotic Kinetochore |
title_fullStr | Functional Redundancy in the Maize Meiotic Kinetochore |
title_full_unstemmed | Functional Redundancy in the Maize Meiotic Kinetochore |
title_short | Functional Redundancy in the Maize Meiotic Kinetochore |
title_sort | functional redundancy in the maize meiotic kinetochore |
topic | Original Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2189807/ https://www.ncbi.nlm.nih.gov/pubmed/11018059 |
work_keys_str_mv | AT yuhongguo functionalredundancyinthemaizemeiotickinetochore AT dawerkelly functionalredundancyinthemaizemeiotickinetochore |