Journal ArticleDOI
X-chromosome inactivation: counting, choice and initiation
Philip Avner,Edith Heard +1 more
TLDR
In many sexually dimorphic species, a mechanism is required to ensure equivalent levels of gene expression from the sex chromosomes, and in mammals, such dosage compensation is achieved by X-chromosome inactivation, a process that presents a unique medley of biological puzzles.Abstract:
In many sexually dimorphic species, a mechanism is required to ensure equivalent levels of gene expression from the sex chromosomes. In mammals, such dosage compensation is achieved by X-chromosome inactivation, a process that presents a unique medley of biological puzzles: how to silence one but not the other X chromosome in the same nucleus; how to count the number of X's and keep only one active; how to choose which X chromosome is inactivated; and how to establish this silent state rapidly and efficiently during early development. The key to most of these puzzles lies in a unique locus, the X-inactivation centre and a remarkable RNA — Xist — that it encodes.read more
Citations
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Journal ArticleDOI
Viability of X-autosome translocations in mammals: an epigenomic hypothesis from a rodent case-study.
TL;DR: An epigenomic hypothesis is proposed which posits that constitutive heterochromatin is probably selected for in X-autosome translocations since it may protect the inactivated X from spreading to the autosomal part, and allow for the independent regulation of replication timing of the sex and autosomal segments.
Journal ArticleDOI
Global and gene-specific methylation patterns in cancer: aspects of tumor biology and clinical potential.
TL;DR: The following minireview covers aspects of the basic molecular biology of DNA methylation and summarizes its importance in human cancers.
Journal ArticleDOI
Lifting a chromosome: dosage compensation in Drosophila melanogaster.
TL;DR: A number of recent publications have furthered the understanding of the ribonucleoprotein complex, which mediates dosage compensation and how it targets the male X chromosome.
Journal ArticleDOI
Expression of the disease on female carriers of X-linked lysosomal disorders: a brief review
Louise Lapagesse de Camargo Pinto,Taiane Alves Vieira,Roberto Giugliani,Ida Vanessa Doederlein Schwartz +3 more
TL;DR: These two X-linked LDs, Fabry disease and MPS II, are reviewed in order to discuss the mechanisms that could explain the different rates of penetrance and expressivity observed in the heterozygotes; this could be helpful to better understand the expression of X-links.
Journal ArticleDOI
Identification of loci that cause phenotypic variation in diverse species with the reciprocal hemizygosity test.
TL;DR: The reciprocal hemizygosity test is a straightforward genetic test that can positively identify genes that have evolved to contribute to a phenotypic difference between strains or between species.
References
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Journal ArticleDOI
Rett syndrome is caused by mutations in X-linked MECP2, encoding methyl-CpG-binding protein 2.
Ruthie E. Amir,Ignatia B. Van den Veyver,Mimi Wan,Charles Q. Tran,Uta Francke,Huda Y. Zoghbi +5 more
TL;DR: This study reports the first disease-causing mutations in RTT and points to abnormal epigenetic regulation as the mechanism underlying the pathogenesis of RTT.
Journal ArticleDOI
Demethylation of the zygotic paternal genome
TL;DR: It is shown that the paternal genome in the mouse is significantly and actively demethylated within 6–8 hours of fertilization, before the onset of DNA replication, whereas the maternal genome is dem methylated after several cleavage divisions.
Journal ArticleDOI
Requirement for Xist in X chromosome inactivation
Graeme D. Penny,Graham F. Kay,Graham F. Kay,Steven A. Sheardown,Sohaila Rastan,Sohaila Rastan,Neil Brockdorff +6 more
TL;DR: Evidence for gene targeting of Xist, the proposed candidate for the X inactivation centre, is provided, and its absolute requirement in the process of X chromosome inactivation is provided.
Journal ArticleDOI
Chromosome instability and immunodeficiency syndrome caused by mutations in a DNA methyltransferase gene.
Guoliang Xu,Timothy H. Bestor,Déborah Bourc'his,Chih-Lin Hsieh,Niels Tommerup,Merete Bugge,Maj Hultén,Xiaoyan Qu,James J. Russo,E. Viegas-Péquignot +9 more
TL;DR: It is shown that five unrelated ICF patients have mutations in both alleles of the gene that encodes DNA methyltransferase 3B (refs 5, 6), which is the only genetic disorder known to involve constitutive abnormalities of genomic methylation patterns.
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Tsix , a gene antisense to Xist at the X-inactivation centre
TL;DR: Tsix RNA is a 40-kb RNA originating 15 kb downstream of Xist and transcribed across the Xist locus and has features suggesting a role in regulating the early steps of X inactivation, but not the silencing step.