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Kinetochore-driven outgrowth of microtubules is a central contributor to kinetochore fiber maturation in crane-fly spermatocytes

We use liquid crystal polarized light imaging to record the life histories of single kinetochore (K-) fibers in living crane-fly spermatocytes, from their origins as nascent K-fibers in early prometaphase to their fully matured form at metaphase, just before anaphase onset. Increased image brightnes...

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Detalles Bibliográficos
Autores principales: LaFountain, James R., Oldenbourg, Rudolf
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The American Society for Cell Biology 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4004593/
https://www.ncbi.nlm.nih.gov/pubmed/24574457
http://dx.doi.org/10.1091/mbc.E14-01-0008
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author LaFountain, James R.
Oldenbourg, Rudolf
author_facet LaFountain, James R.
Oldenbourg, Rudolf
author_sort LaFountain, James R.
collection PubMed
description We use liquid crystal polarized light imaging to record the life histories of single kinetochore (K-) fibers in living crane-fly spermatocytes, from their origins as nascent K-fibers in early prometaphase to their fully matured form at metaphase, just before anaphase onset. Increased image brightness due to increased retardance reveals where microtubules are added during K-fiber formation. Analysis of experimentally generated bipolar spindles with only one centrosome, as well as of regular, bicentrosomal spindles, reveals that microtubule addition occurs at the kinetochore-proximal ends of K-fibers, and added polymer expands poleward, giving rise to the robust K-fibers of metaphase cells. These results are not compatible with a model for K-fiber formation in which microtubules are added to nascent fibers solely by repetitive “search and capture” of centrosomal microtubule plus ends. Our interpretation is that capture of centrosomal microtubules—when deployed—is limited to early stages in establishment of nascent K-fibers, which then mature through kinetochore-driven outgrowth. When kinetochore capture of centrosomal microtubules is not used, the polar ends of K-fibers grow outward from their kinetochores and usually converge to make a centrosome-free pole.
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spelling pubmed-40045932014-07-16 Kinetochore-driven outgrowth of microtubules is a central contributor to kinetochore fiber maturation in crane-fly spermatocytes LaFountain, James R. Oldenbourg, Rudolf Mol Biol Cell Articles We use liquid crystal polarized light imaging to record the life histories of single kinetochore (K-) fibers in living crane-fly spermatocytes, from their origins as nascent K-fibers in early prometaphase to their fully matured form at metaphase, just before anaphase onset. Increased image brightness due to increased retardance reveals where microtubules are added during K-fiber formation. Analysis of experimentally generated bipolar spindles with only one centrosome, as well as of regular, bicentrosomal spindles, reveals that microtubule addition occurs at the kinetochore-proximal ends of K-fibers, and added polymer expands poleward, giving rise to the robust K-fibers of metaphase cells. These results are not compatible with a model for K-fiber formation in which microtubules are added to nascent fibers solely by repetitive “search and capture” of centrosomal microtubule plus ends. Our interpretation is that capture of centrosomal microtubules—when deployed—is limited to early stages in establishment of nascent K-fibers, which then mature through kinetochore-driven outgrowth. When kinetochore capture of centrosomal microtubules is not used, the polar ends of K-fibers grow outward from their kinetochores and usually converge to make a centrosome-free pole. The American Society for Cell Biology 2014-05-01 /pmc/articles/PMC4004593/ /pubmed/24574457 http://dx.doi.org/10.1091/mbc.E14-01-0008 Text en © 2014 LaFountain and Oldenbourg. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0). “ASCB®,” “The American Society for Cell Biology®,” and “Molecular Biology of the Cell®” are registered trademarks of The American Society of Cell Biology.
spellingShingle Articles
LaFountain, James R.
Oldenbourg, Rudolf
Kinetochore-driven outgrowth of microtubules is a central contributor to kinetochore fiber maturation in crane-fly spermatocytes
title Kinetochore-driven outgrowth of microtubules is a central contributor to kinetochore fiber maturation in crane-fly spermatocytes
title_full Kinetochore-driven outgrowth of microtubules is a central contributor to kinetochore fiber maturation in crane-fly spermatocytes
title_fullStr Kinetochore-driven outgrowth of microtubules is a central contributor to kinetochore fiber maturation in crane-fly spermatocytes
title_full_unstemmed Kinetochore-driven outgrowth of microtubules is a central contributor to kinetochore fiber maturation in crane-fly spermatocytes
title_short Kinetochore-driven outgrowth of microtubules is a central contributor to kinetochore fiber maturation in crane-fly spermatocytes
title_sort kinetochore-driven outgrowth of microtubules is a central contributor to kinetochore fiber maturation in crane-fly spermatocytes
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4004593/
https://www.ncbi.nlm.nih.gov/pubmed/24574457
http://dx.doi.org/10.1091/mbc.E14-01-0008
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