keyword
MENU ▼
Read by QxMD icon Read
search

XCI AND Xist

keyword
https://www.readbyqxmd.com/read/28408975/x-chromosome-inactivation-new-players-in-the-initiation-of-gene-silencing
#1
REVIEW
Ines Pinheiro, Edith Heard
X chromosome inactivation (XCI) is a dosage compensation process that was adopted by female mammals to balance gene dosage between XX females and XY males. XCI starts with the upregulation of the non-coding RNA Xist, after which most X-linked genes are silenced and acquire a repressive chromatin state. Even though the chromatin marks of the inactive X have been fairly well described, the mechanisms responsible for the initiation of XCI remain largely unknown. In this review, we discuss recent developments that revealed unexpected factors playing a role in XCI and that might be of crucial importance to understand the mechanisms responsible for the very first steps of this chromosome-wide gene-silencing event...
2017: F1000Research
https://www.readbyqxmd.com/read/28401797/the-state-of-skewed-x-chromosome-inactivation-is-retained-in-the-induced-pluripotent-stem-cells-from-a-female-with-hemophilia-b
#2
Cuicui Lyu, Jun Shen, Jianping Zhang, Feng Xue, Xiaofan Liu, Wei Liu, Rongfeng Fu, Liyan Zhang, Huiyuan Li, Donglei Zhang, Xiaobing Zhang, Tao Cheng, Renchi Yang, Lei Zhang
Skewed X chromosome inactivation (XCI) is a rare reason for hemophilia B in females. It is indefinite whether X chromosome reactivation (XCR) would occur when cells of hemophilia B patients with skewed XCI were reprogrammed into induced pluripotent stem cells (iPSCs). In this study, we investigated a female hemophilia B patient with a known F9 gene mutation: c.676C>T, p.Arg226Trp . We demonstrated that skewed XCI was the pathogenesis of the patient, and we successfully generated numerous iPSC colonies of the patient from peripheral blood mononuclear cells (PBMNCs), which was the first time for generating hemophilia-specific iPSCs from PBMNCs...
March 22, 2017: Stem Cells and Development
https://www.readbyqxmd.com/read/28387970/mutation-of-the-xist-gene-upregulates-expression-of-x-linked-genes-but-decreases-the-developmental-rates-of-cloned-male-porcine-embryos
#3
Yang Yang, Dan Wu, Dewu Liu, Junsong Shi, Rong Zhou, Xiaoyan He, Jianping Quan, Gengyuan Cai, Enqin Zheng, Zhenfang Wu, Zicong Li
XIST is an X-linked, non-coding gene responsible for the cis induction of X-chromosome inactivation (XCI). Knockout of the XIST allele on an active X chromosome abolishes erroneous XCI and enhances the in vivo development of cloned mouse embryos by more than 10-fold. This study aimed to investigate whether a similar manipulation would improve cloning efficiency in pigs. A male, porcine kidney cell line containing an EGFP insert in exon 1 of the XIST gene, resulting in a knockout allele (XIST-KO), was generated by homologous recombination using transcription activator-like effector nucleases (TALENs)...
April 7, 2017: Molecular Reproduction and Development
https://www.readbyqxmd.com/read/28368037/high-resolution-rna-allelotyping-along-the-inactive-x-chromosome-evidence-of-rna-polymerase-iii-in-regulating-chromatin-configuration
#4
Ru Hong, Bingqing Lin, Xinyi Lu, Lan-Tian Lai, Xin Chen, Amartya Sanyal, Huck-Hui Ng, Kun Zhang, Li-Feng Zhang
We carried out padlock capture, a high-resolution RNA allelotyping method, to study X chromosome inactivation (XCI). We examined the gene reactivation pattern along the inactive X (Xi), after Xist (X-inactive specific transcript), a prototype long non-coding RNA essential for establishing X chromosome inactivation (XCI) in early embryos, is conditionally deleted from Xi in somatic cells (Xi(∆Xist)). We also monitored the behaviors of X-linked non-coding transcripts before and after XCI. In each mutant cell line, gene reactivation occurs to ~6% genes along Xi(∆Xist) in a recognizable pattern...
April 3, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28257137/novel-players-in-x-inactivation-insights-into-xist-mediated-gene-silencing-and-chromosome-conformation
#5
REVIEW
Simão T da Rocha, Edith Heard
The nuclear long noncoding RNA (lncRNA) Xist ensures X-chromosome inactivation (XCI) in female placental mammals. Although Xist is one of the most intensively studied lncRNAs, the mechanisms associated with its capacity to trigger chromosome-wide gene silencing, the formation of facultative heterochromatin and an unusual 3D conformation of the inactive X chromosome (Xi) have remained elusive. Now researchers have identified novel functional partners of Xist in a series of breakthrough studies, using unbiased techniques to isolate Xist-bound proteins, as well as forward genetic screens...
March 3, 2017: Nature Structural & Molecular Biology
https://www.readbyqxmd.com/read/28236732/x-chromosome-inactivation-silencing-topology-and-reactivation
#6
REVIEW
Teresa Robert Finestra, Joost Gribnau
To ensure X-linked gene dosage compensation between females (XX) and males (XY), one X chromosome undergoes X chromosome inactivation (XCI) in female cells. This process is tightly regulated throughout development by many different factors, with Xist as a key regulator, encoding a long non-coding RNA, involved in establishment of several layers of repressive epigenetic modifications. Several recent studies on XCI focusing on identification and characterization of Xist RNA-protein interactors, revealed new factors involved in gene silencing, genome topology and nuclear membrane attachment, amongst others...
February 21, 2017: Current Opinion in Cell Biology
https://www.readbyqxmd.com/read/27716834/round-spermatid-injection-rescues-female-lethality-of-a-paternally-inherited-xist-deletion-in-mouse
#7
Federica Federici, Aristea Magaraki, Evelyne Wassenaar, Catherina J H van Veen-Buurman, Christine van de Werken, Esther B Baart, Joop S E Laven, J Anton Grootegoed, Joost Gribnau, Willy M Baarends
In mouse female preimplantation embryos, the paternal X chromosome (Xp) is silenced by imprinted X chromosome inactivation (iXCI). This requires production of the noncoding Xist RNA in cis, from the Xp. The Xist locus on the maternally inherited X chromosome (Xm) is refractory to activation due to the presence of an imprint. Paternal inheritance of an Xist deletion (XpΔXist) is embryonic lethal to female embryos, due to iXCI abolishment. Here, we circumvented the histone-to-protamine and protamine-to-histone transitions of the paternal genome, by fertilization of oocytes via injection of round spermatids (ROSI)...
October 2016: PLoS Genetics
https://www.readbyqxmd.com/read/27542829/female-mice-lacking-xist-rna-show-partial-dosage-compensation-and-survive-to-term
#8
Lin Yang, James E Kirby, Hongjae Sunwoo, Jeannie T Lee
X-chromosome inactivation (XCI) compensates for differences in X-chromosome number between male and female mammals. XCI is orchestrated by Xist RNA, whose expression in early development leads to transcriptional silencing of one X chromosome in the female. Knockout studies have established a requirement for Xist with inviability of female embryos that inherit an Xist deletion from the father. Here, we report that female mice lacking Xist RNA can, surprisingly, develop and survive to term. Xist-null females are born at lower frequency and are smaller at birth, but organogenesis is mostly normal...
August 1, 2016: Genes & Development
https://www.readbyqxmd.com/read/27528619/xist-and-tsix-transcription-dynamics-is-regulated-by-the-x-to-autosome-ratio-and-semistable-transcriptional-states
#9
Friedemann Loos, Cheryl Maduro, Agnese Loda, Johannes Lehmann, Gert-Jan Kremers, Derk Ten Berge, J Anton Grootegoed, Joost Gribnau
In female mammals, X chromosome inactivation (XCI) is a key process in the control of gene dosage compensation between X-linked genes and autosomes. Xist and Tsix, two overlapping antisense-transcribed noncoding genes, are central elements of the X inactivation center (Xic) regulating XCI. Xist upregulation results in the coating of the entire X chromosome by Xist RNA in cis, whereas Tsix transcription acts as a negative regulator of Xist Here, we generated Xist and Tsix reporter mouse embryonic stem (ES) cell lines to study the genetic and dynamic regulation of these genes upon differentiation...
November 1, 2016: Molecular and Cellular Biology
https://www.readbyqxmd.com/read/27504142/thoughts-about-slc16a2-tsix-and-xist-gene-like-sites-in-the-human-genome-and-a-potential-role-in-cellular-chromosome-counting
#10
Martina Rinčić, Ivan Y Iourov, Thomas Liehr
BACKGROUND: Chromosome counting is a process in which cells determine somehow their intrinsic chromosome number(s). The best-studied cellular mechanism that involves chromosome counting is 'chromosome-kissing' and X-chromosome inactivation (XCI) mechanism. It is necessary for the well-known dosage compensation between the genders in mammals to balance the number of active X-chromosomes (Xa) with regard to diploid set of autosomes. At the onset of XCI, two X-chromosomes are coming in close proximity and pair physically by a specific segment denominated X-pairing region (Xpr) that involves the SLC16A2 gene...
2016: Molecular Cytogenetics
https://www.readbyqxmd.com/read/27437574/structural-organization-of-the-inactive-x-chromosome-in-the-mouse
#11
Luca Giorgetti, Bryan R Lajoie, Ava C Carter, Mikael Attia, Ye Zhan, Jin Xu, Chong Jian Chen, Noam Kaplan, Howard Y Chang, Edith Heard, Job Dekker
X-chromosome inactivation (XCI) involves major reorganization of the X chromosome as it becomes silent and heterochromatic. During female mammalian development, XCI is triggered by upregulation of the non-coding Xist RNA from one of the two X chromosomes. Xist coats the chromosome in cis and induces silencing of almost all genes via its A-repeat region, although some genes (constitutive escapees) avoid silencing in most cell types, and others (facultative escapees) escape XCI only in specific contexts. A role for Xist in organizing the inactive X (Xi) chromosome has been proposed...
July 28, 2016: Nature
https://www.readbyqxmd.com/read/27262949/the-dynamic-changes-of-x-chromosome-inactivation-during-early-culture-of-human-embryonic-stem-cells
#12
Pingyuan Xie, Qi Ouyang, Lizhi Leng, Liang Hu, Dehua Cheng, Yueqiu Tan, Guangxiu Lu, Ge Lin
X chromosome inactivation (XCI) is required for dosage compensation of X-linked genes in human female cells. Several previous reports have described the promiscuous XCI status in long-term cultured female human embryonic stem cells (hESCs), and the majority of them exhibit non-random XCI. However, when and how such female hESCs acquire the aberrant XCI states during culture is unknown. Herein, through comparing the XCI states in 18 paired hES cell lines throughout early culture, we revealed a uniform dynamic change during this culture period under a widely used culture condition...
July 2016: Stem Cell Research
https://www.readbyqxmd.com/read/27173581/function-and-evolution-of-the-long-noncoding-rna-circuitry-orchestrating-x-chromosome-inactivation-in-mammals
#13
REVIEW
Giulia Furlan, Claire Rougeulle
X-chromosome inactivation (XCI) is a chromosome-wide regulatory process that ensures dosage compensation for X-linked genes in Theria. XCI is established during early embryogenesis and is developmentally regulated. Different XCI strategies exist in mammalian infraclasses and the regulation of this process varies also among closely related species. In Eutheria, initiation of XCI is orchestrated by a cis-acting locus, the X-inactivation center (Xic), which is particularly enriched in genes producing long noncoding RNAs (lncRNAs)...
September 2016: Wiley Interdisciplinary Reviews. RNA
https://www.readbyqxmd.com/read/27115694/new-xist-interacting-proteins-in-x-chromosome-inactivation
#14
REVIEW
Hegias Mira-Bontenbal, Joost Gribnau
To achieve dosage compensation of X-linked gene expression, female mammalian cells inactivate one X chromosome through a process called X-chromosome inactivation (XCI). A central component of this process is the X-encoded long non-coding RNA Xist. Following upregulation from one X chromosome, Xist spreads in cis, kicking off a plethora of events that ultimately results in stable X-linked gene repression, which is then faithfully transmitted to all daughter cells. In the last decades, intensive work has been undertaken to understand each of the steps in XCI, namely Xist transcription control, Xist spreading and localization, and silencing of gene expression...
April 25, 2016: Current Biology: CB
https://www.readbyqxmd.com/read/27072488/a-tale-of-two-cities-how-xist-and-its-partners-localize-to-and-silence-the-bicompartmental-x
#15
REVIEW
Stefan F Pinter
Sex chromosomal dosage compensation in mammals takes the form of X chromosome inactivation (XCI), driven by the non-coding RNA Xist. In contrast to dosage compensation systems of flies and worms, mammalian XCI has to restrict its function to the Xist-producing X chromosome, while leaving autosomes and active X untouched. The mechanisms behind the long-range yet cis-specific localization and silencing activities of Xist have long been enigmatic, but genomics, proteomics, super-resolution microscopy, and innovative genetic approaches have produced significant new insights in recent years...
August 2016: Seminars in Cell & Developmental Biology
https://www.readbyqxmd.com/read/27062886/the-lnc-between-3d-chromatin-structure-and-x-chromosome-inactivation
#16
REVIEW
Amy Pandya-Jones, Kathrin Plath
The long non-coding RNA Xist directs a remarkable instance of developmentally regulated, epigenetic change known as X Chromosome Inactivation (XCI). By spreading in cis across the X chromosome from which it is expressed, Xist RNA facilitates the creation of a heritably silent, heterochromatic nuclear territory that displays a three-dimensional structure distinct from that of the active X chromosome. How Xist RNA attaches to and propagates across a chromosome and its influence over the three-dimensional (3D) structure of the inactive X are aspects of XCI that have remained largely unclear...
August 2016: Seminars in Cell & Developmental Biology
https://www.readbyqxmd.com/read/27001848/unusual-maintenance-of-x-chromosome-inactivation-predisposes-female-lymphocytes-for-increased-expression-from-the-inactive-x
#17
Jianle Wang, Camille M Syrett, Marianne C Kramer, Arindam Basu, Michael L Atchison, Montserrat C Anguera
Females have a greater immunological advantage than men, yet they are more prone to autoimmune disorders. The basis for this sex bias lies in the X chromosome, which contains many immunity-related genes. Female mammals use X chromosome inactivation (XCI) to generate a transcriptionally silent inactive X chromosome (Xi) enriched with heterochromatic modifications and XIST/Xist RNA, which equalizes gene expression between the sexes. Here, we examine the maintenance of XCI in lymphocytes from females in mice and humans...
April 5, 2016: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/26786180/female-human-pluripotent-stem-cells-rapidly-lose-x-chromosome-inactivation-marks-and-progress-to-a-skewed-methylation-pattern-during-culture
#18
M Geens, A Seriola, L Barbé, J Santalo, A Veiga, K Dée, L Van Haute, K Sermon, C Spits
STUDY HYPOTHESIS: Does a preferential X chromosome inactivation (XCI) pattern exist in female human pluripotent stem cells (hPSCs) and does the pattern change during long-term culture or upon differentiation? STUDY FINDING: We identified two independent phenomena that lead to aberrant XCI patterns in female hPSC: a rapid loss of histone H3 lysine 27 trimethylation (H3K27me3) and long non-coding X-inactive specific transcript (XIST) expression during culture, often accompanied by erosion of XCI-specific methylation, and a frequent loss of random XCI in the cultures...
April 2016: Molecular Human Reproduction
https://www.readbyqxmd.com/read/26659486/how-many-non-coding-rnas-does-it-take-to-compensate-male-female-genetic-imbalance
#19
REVIEW
Jean-François Ouimette, Claire Rougeulle
Genetic sex determination in mammals relies on dimorphic sex chromosomes that confer phenotypic/physiologic differences between males and females. In this heterogametic system, X and Y chromosomes diverged from an ancestral pair of autosomes, creating a genetic disequilibrium between XX females and XY males. Dosage compensation mechanisms alleviate intrinsic gene dosage imbalance, leading to equal expression levels of most X-linked genes in the two sexes. In therian mammals, this is achieved through inactivation of one of the two X chromosomes in females...
2016: Advances in Experimental Medicine and Biology
https://www.readbyqxmd.com/read/26598280/dosage-compensation-of-x-chromosome-inactivation-center-linked-genes-in-porcine-preimplantation-embryos-non-chromosome-wide-initiation-of-x-chromosome-inactivation-in-blastocysts
#20
Jae Yeon Hwang, Jong-Nam Oh, Chi-Hun Park, Dong-Kyung Lee, Chang-Kyu Lee
X-chromosome inactivation (XCI) is an epigenetic mechanism that occurs in the eutherian embryo development to equalize the dosage of X-linked genes between males and females. This event is regulated by various factors, and the genes located in the X-chromosome inactivation center (XIC), which is known to be an evolutionary conserved region, are associated with XCI; however, a number of studies regarding this epigenetic event and genomic region are primarily performed in mouse models despite its species-specific features...
November 2015: Mechanisms of Development
keyword
keyword
83002
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"