Tag Archives: XIST

Featured long non-coding RNA – XACT

lncRNA

X-chromosome inactivation (XCI) in mammals relies on XIST, a long noncoding transcript that coats and silences the X chromosome in cis. Here researchers from Université Paris Diderot, France report the discovery of a long noncoding RNA, XACT, that is expressed from and coats the active X chromosome specifically in human pluripotent cells. In the absence of XIST, XACT is expressed ...

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The Xist lncRNA Exploits Three-Dimensional Genome Architecture to Spread Across the X Chromosome

lncRNA

Mammalian genomes encode thousands of large noncoding RNAs (lncRNAs), many of which regulate gene expression, interact with chromatin regulatory complexes, and are thought to play a role in localizing these complexes to target loci across the genome. A paradigm for this class of lncRNAs is Xist, which orchestrates mammalian X-chromosome inactivation (XCI) by coating and silencing one X chromosome in ...

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Switching Off The Extra Chromosome Provides Major Breakthrough In Down’s Syndrome Research

by Susan Bowen for redOrbit.com – Your Universe Online Scientists at the University of Massachusetts Medical School have made a huge breakthrough in our understanding of Down’s syndrome. They reported in the online science journal Nature, that in a lab, they have switched off the extra chromosome that causes the disorder in humans. This is the proof-of-principal that opens the ...

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Jpx RNA Activates Xist by Evicting CTCF

In mammals, dosage compensation between XX and XY individuals occurs through X chromosome inactivation (XCI). The noncoding Xist RNA is expressed and initiates XCI only when more than one X chromosome is present. Current models invoke a dependency on the X-to-autosome ratio (X:A), but molecular factors remain poorly defined. Here, researchers at the Howard Hughes Medical Institute demonstrate that molecular ...

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Shedding Light on Unique RNAs

from Bioscience Technology The genes that code for proteins—more than 20,000 in total—make up only about 1 percent of the complete human genome. That entire thing—not just the genes, but also genetic junk and all the rest—is coiled and folded up in any number of ways within the nucleus of each of our cells. Think, then, of the challenge that ...

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Advances in understanding chromosome silencing by the long non-coding RNA Xist

In female mammals, one of the two X chromosomes becomes genetically silenced to compensate for dosage imbalance of X-linked genes between XX females and XY males. X chromosome inactivation (X-inactivation) is a classical model for epigenetic gene regulation in mammals and has been studied for half a century. In the last two decades, efforts have been focused on the X ...

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Long non-coding RNA Xist is a potent suppressor of hematologic cancer

XIST

X chromosome aneuploidies have long been associated with human cancers, but causality has not been established. In mammals, X chromosome inactivation (XCI) is triggered by Xist RNA to equalize gene expression between the sexes. Here, researchers from Massachusetts General Hospital delete Xist in the blood compartment of mice and demonstrate that mutant females develop a highly aggressive myeloproliferative neoplasm and ...

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Long non-coding RNAs as targets for cytosine methylation

Post-synthetic modifications of nucleic acids have long been known to affect their functional and structural properties. For instance, numerous different chemical modifications modulate the structural organization, stability or translation efficiency of tRNAs and rRNAs. In contrast, little is known about modifications of poly(A)RNAs. Here, researchers from the Innsbruck Medical University, Austria demonstrate for the first time that the two well-studied ...

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