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Judging Diatoms by Their Cover: Variability in Local Elasticity of Lithodesmium undulatum Undergoing Cell Division

Unique features of diatoms are their intricate cell covers (frustules) made out of hydrated, amorphous silica. The frustule defines and maintains cell shape and protects cells against grazers and pathogens, yet it must allow for cell expansion during growth and division. Other siliceous structures h...

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Autores principales: Karp-Boss, Lee, Gueta, Rachel, Rousso, Itay
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4206279/
https://www.ncbi.nlm.nih.gov/pubmed/25337801
http://dx.doi.org/10.1371/journal.pone.0109089
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author Karp-Boss, Lee
Gueta, Rachel
Rousso, Itay
author_facet Karp-Boss, Lee
Gueta, Rachel
Rousso, Itay
author_sort Karp-Boss, Lee
collection PubMed
description Unique features of diatoms are their intricate cell covers (frustules) made out of hydrated, amorphous silica. The frustule defines and maintains cell shape and protects cells against grazers and pathogens, yet it must allow for cell expansion during growth and division. Other siliceous structures have also evolved in some chain-forming species as means for holding neighboring cells together. Characterization and quantification of mechanical properties of these structures are crucial for the understanding of the relationship between form and function in diatoms, but thus far only a handful of studies have addressed this issue. We conducted micro-indentation experiments, using atomic force microscopy (AFM), to examine local variations in elastic (Young's) moduli of cells and linking structures in the marine, chain-forming diatom Lithodesmium undulatum. Using a fluorescent tracer that is incorporated into new cell wall components we tested the hypothesis that new siliceous structures differ in elastic modulus from their older counterparts. Results show that the local elastic modulus is a highly dynamic property. Elastic modulus of stained regions was significantly lower than that of unstained regions, suggesting that newly formed cell wall components are generally softer than the ones inherited from the parent cells. This study provides the first evidence of differentiation in local elastic properties in the course of the cell cycle. Hardening of newly formed regions may involve incorporation of additional, possibly organic, material but further studies are needed to elucidate the processes that regulate mechanical properties of the frustule during the cell cycle.
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spelling pubmed-42062792014-10-27 Judging Diatoms by Their Cover: Variability in Local Elasticity of Lithodesmium undulatum Undergoing Cell Division Karp-Boss, Lee Gueta, Rachel Rousso, Itay PLoS One Research Article Unique features of diatoms are their intricate cell covers (frustules) made out of hydrated, amorphous silica. The frustule defines and maintains cell shape and protects cells against grazers and pathogens, yet it must allow for cell expansion during growth and division. Other siliceous structures have also evolved in some chain-forming species as means for holding neighboring cells together. Characterization and quantification of mechanical properties of these structures are crucial for the understanding of the relationship between form and function in diatoms, but thus far only a handful of studies have addressed this issue. We conducted micro-indentation experiments, using atomic force microscopy (AFM), to examine local variations in elastic (Young's) moduli of cells and linking structures in the marine, chain-forming diatom Lithodesmium undulatum. Using a fluorescent tracer that is incorporated into new cell wall components we tested the hypothesis that new siliceous structures differ in elastic modulus from their older counterparts. Results show that the local elastic modulus is a highly dynamic property. Elastic modulus of stained regions was significantly lower than that of unstained regions, suggesting that newly formed cell wall components are generally softer than the ones inherited from the parent cells. This study provides the first evidence of differentiation in local elastic properties in the course of the cell cycle. Hardening of newly formed regions may involve incorporation of additional, possibly organic, material but further studies are needed to elucidate the processes that regulate mechanical properties of the frustule during the cell cycle. Public Library of Science 2014-10-22 /pmc/articles/PMC4206279/ /pubmed/25337801 http://dx.doi.org/10.1371/journal.pone.0109089 Text en © 2014 Karp-Boss et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Karp-Boss, Lee
Gueta, Rachel
Rousso, Itay
Judging Diatoms by Their Cover: Variability in Local Elasticity of Lithodesmium undulatum Undergoing Cell Division
title Judging Diatoms by Their Cover: Variability in Local Elasticity of Lithodesmium undulatum Undergoing Cell Division
title_full Judging Diatoms by Their Cover: Variability in Local Elasticity of Lithodesmium undulatum Undergoing Cell Division
title_fullStr Judging Diatoms by Their Cover: Variability in Local Elasticity of Lithodesmium undulatum Undergoing Cell Division
title_full_unstemmed Judging Diatoms by Their Cover: Variability in Local Elasticity of Lithodesmium undulatum Undergoing Cell Division
title_short Judging Diatoms by Their Cover: Variability in Local Elasticity of Lithodesmium undulatum Undergoing Cell Division
title_sort judging diatoms by their cover: variability in local elasticity of lithodesmium undulatum undergoing cell division
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4206279/
https://www.ncbi.nlm.nih.gov/pubmed/25337801
http://dx.doi.org/10.1371/journal.pone.0109089
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