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Ribosomal DNA loci derived from Brachypodium stacei are switched off for major parts of the life cycle of Brachypodium hybridum
Nucleolar dominance is an epigenetic phenomenon that occurs in some plant and animal allopolyploids and hybrids, whereby only one ancestral set of 35S rRNA genes retains the ability to form the nucleolus while the rDNA loci derived from the other progenitor are transcriptionally silenced. There is s...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Oxford University Press
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6363085/ https://www.ncbi.nlm.nih.gov/pubmed/30481334 http://dx.doi.org/10.1093/jxb/ery425 |
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author | Borowska-Zuchowska, Natalia Robaszkiewicz, Ewa Wolny, Elzbieta Betekhtin, Alexander Hasterok, Robert |
author_facet | Borowska-Zuchowska, Natalia Robaszkiewicz, Ewa Wolny, Elzbieta Betekhtin, Alexander Hasterok, Robert |
author_sort | Borowska-Zuchowska, Natalia |
collection | PubMed |
description | Nucleolar dominance is an epigenetic phenomenon that occurs in some plant and animal allopolyploids and hybrids, whereby only one ancestral set of 35S rRNA genes retains the ability to form the nucleolus while the rDNA loci derived from the other progenitor are transcriptionally silenced. There is substantial evidence that nucleolar dominance is regulated developmentally. This study focuses upon the establishment and/or maintenance of nucleolar dominance during different stages of development in the model grass allotetraploid Brachypodium hybridum. Fluorescence in situ hybridization with a 25S rDNA probe to cells in three-dimensional cytogenetic preparations showed that nucleolar dominance is present not only in root meristematic and differentiated cells of this species, but also in male meiocytes at prophase I, tetrads of microspores, and different embryonic tissues. The inactive state of Brachypodium stacei-originated rDNA loci was confirmed by silver staining. Only B. distachyon-derived 35S rDNA loci formed nucleoli in the aforementioned tissues, whereas B. stacei-like loci remained highly condensed and thus transcriptionally suppressed. The establishment of nucleolar dominance during earlier stages of B. hybridum embryo development cannot be ruled out. However, we propose that gradual pseudogenization of B. stacei-like loci in the evolution of the allotetraploid seems to be more likely. |
format | Online Article Text |
id | pubmed-6363085 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | Oxford University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-63630852019-02-08 Ribosomal DNA loci derived from Brachypodium stacei are switched off for major parts of the life cycle of Brachypodium hybridum Borowska-Zuchowska, Natalia Robaszkiewicz, Ewa Wolny, Elzbieta Betekhtin, Alexander Hasterok, Robert J Exp Bot Research Papers Nucleolar dominance is an epigenetic phenomenon that occurs in some plant and animal allopolyploids and hybrids, whereby only one ancestral set of 35S rRNA genes retains the ability to form the nucleolus while the rDNA loci derived from the other progenitor are transcriptionally silenced. There is substantial evidence that nucleolar dominance is regulated developmentally. This study focuses upon the establishment and/or maintenance of nucleolar dominance during different stages of development in the model grass allotetraploid Brachypodium hybridum. Fluorescence in situ hybridization with a 25S rDNA probe to cells in three-dimensional cytogenetic preparations showed that nucleolar dominance is present not only in root meristematic and differentiated cells of this species, but also in male meiocytes at prophase I, tetrads of microspores, and different embryonic tissues. The inactive state of Brachypodium stacei-originated rDNA loci was confirmed by silver staining. Only B. distachyon-derived 35S rDNA loci formed nucleoli in the aforementioned tissues, whereas B. stacei-like loci remained highly condensed and thus transcriptionally suppressed. The establishment of nucleolar dominance during earlier stages of B. hybridum embryo development cannot be ruled out. However, we propose that gradual pseudogenization of B. stacei-like loci in the evolution of the allotetraploid seems to be more likely. Oxford University Press 2019-01-30 2018-11-27 /pmc/articles/PMC6363085/ /pubmed/30481334 http://dx.doi.org/10.1093/jxb/ery425 Text en © The Author(s) 2018. Published by Oxford University Press on behalf of the Society for Experimental Biology. http://creativecommons.org/licenses/by/4.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Research Papers Borowska-Zuchowska, Natalia Robaszkiewicz, Ewa Wolny, Elzbieta Betekhtin, Alexander Hasterok, Robert Ribosomal DNA loci derived from Brachypodium stacei are switched off for major parts of the life cycle of Brachypodium hybridum |
title | Ribosomal DNA loci derived from Brachypodium stacei are switched off for major parts of the life cycle of Brachypodium hybridum |
title_full | Ribosomal DNA loci derived from Brachypodium stacei are switched off for major parts of the life cycle of Brachypodium hybridum |
title_fullStr | Ribosomal DNA loci derived from Brachypodium stacei are switched off for major parts of the life cycle of Brachypodium hybridum |
title_full_unstemmed | Ribosomal DNA loci derived from Brachypodium stacei are switched off for major parts of the life cycle of Brachypodium hybridum |
title_short | Ribosomal DNA loci derived from Brachypodium stacei are switched off for major parts of the life cycle of Brachypodium hybridum |
title_sort | ribosomal dna loci derived from brachypodium stacei are switched off for major parts of the life cycle of brachypodium hybridum |
topic | Research Papers |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6363085/ https://www.ncbi.nlm.nih.gov/pubmed/30481334 http://dx.doi.org/10.1093/jxb/ery425 |
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