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The Demoiselle of X-Inactivation: 50 Years Old and As Trendy and Mesmerising As Ever
In humans, sexual dimorphism is associated with the presence of two X chromosomes in the female, whereas males possess only one X and a small and largely degenerate Y chromosome. How do men cope with having only a single X chromosome given that virtually all other chromosomal monosomies are lethal?...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2011
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3141017/ https://www.ncbi.nlm.nih.gov/pubmed/21811421 http://dx.doi.org/10.1371/journal.pgen.1002212 |
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author | Morey, Céline Avner, Philip |
author_facet | Morey, Céline Avner, Philip |
author_sort | Morey, Céline |
collection | PubMed |
description | In humans, sexual dimorphism is associated with the presence of two X chromosomes in the female, whereas males possess only one X and a small and largely degenerate Y chromosome. How do men cope with having only a single X chromosome given that virtually all other chromosomal monosomies are lethal? Ironically, or even typically many might say, women and more generally female mammals contribute most to the job by shutting down one of their two X chromosomes at random. This phenomenon, called X-inactivation, was originally described some 50 years ago by Mary Lyon and has captivated an increasing number of scientists ever since. The fascination arose in part from the realisation that the inactive X corresponded to a dense heterochromatin mass called the “Barr body” whose number varied with the number of Xs within the nucleus and from the many intellectual questions that this raised: How does the cell count the X chromosomes in the nucleus and inactivate all Xs except one? What kind of molecular mechanisms are able to trigger such a profound, chromosome-wide metamorphosis? When is X-inactivation initiated? How is it transmitted to daughter cells and how is it reset during gametogenesis? This review retraces some of the crucial findings, which have led to our current understanding of a biological process that was initially considered as an exception completely distinct from conventional regulatory systems but is now viewed as a paradigm “par excellence” for epigenetic regulation. |
format | Online Article Text |
id | pubmed-3141017 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2011 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-31410172011-08-02 The Demoiselle of X-Inactivation: 50 Years Old and As Trendy and Mesmerising As Ever Morey, Céline Avner, Philip PLoS Genet Review In humans, sexual dimorphism is associated with the presence of two X chromosomes in the female, whereas males possess only one X and a small and largely degenerate Y chromosome. How do men cope with having only a single X chromosome given that virtually all other chromosomal monosomies are lethal? Ironically, or even typically many might say, women and more generally female mammals contribute most to the job by shutting down one of their two X chromosomes at random. This phenomenon, called X-inactivation, was originally described some 50 years ago by Mary Lyon and has captivated an increasing number of scientists ever since. The fascination arose in part from the realisation that the inactive X corresponded to a dense heterochromatin mass called the “Barr body” whose number varied with the number of Xs within the nucleus and from the many intellectual questions that this raised: How does the cell count the X chromosomes in the nucleus and inactivate all Xs except one? What kind of molecular mechanisms are able to trigger such a profound, chromosome-wide metamorphosis? When is X-inactivation initiated? How is it transmitted to daughter cells and how is it reset during gametogenesis? This review retraces some of the crucial findings, which have led to our current understanding of a biological process that was initially considered as an exception completely distinct from conventional regulatory systems but is now viewed as a paradigm “par excellence” for epigenetic regulation. Public Library of Science 2011-07-21 /pmc/articles/PMC3141017/ /pubmed/21811421 http://dx.doi.org/10.1371/journal.pgen.1002212 Text en Morey, Avner. 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 | Review Morey, Céline Avner, Philip The Demoiselle of X-Inactivation: 50 Years Old and As Trendy and Mesmerising As Ever |
title | The Demoiselle of X-Inactivation: 50 Years Old and As Trendy and Mesmerising As Ever |
title_full | The Demoiselle of X-Inactivation: 50 Years Old and As Trendy and Mesmerising As Ever |
title_fullStr | The Demoiselle of X-Inactivation: 50 Years Old and As Trendy and Mesmerising As Ever |
title_full_unstemmed | The Demoiselle of X-Inactivation: 50 Years Old and As Trendy and Mesmerising As Ever |
title_short | The Demoiselle of X-Inactivation: 50 Years Old and As Trendy and Mesmerising As Ever |
title_sort | demoiselle of x-inactivation: 50 years old and as trendy and mesmerising as ever |
topic | Review |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3141017/ https://www.ncbi.nlm.nih.gov/pubmed/21811421 http://dx.doi.org/10.1371/journal.pgen.1002212 |
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