What is the Xist gene?
Xist (X-inactive specific transcript) is a non-coding RNA on the X chromosome of the placental mammals that acts as a major effector of the X-inactivation process. It is a component of the Xic – X-chromosome inactivation centre – along with two other RNA genes (Jpx and Ftx) and two protein genes (Tsx and Cnbp2).
What is the product of the Xist gene?
The product of the mouse Xist gene is a 15 kb inactive X-specific transcript containing no conserved ORF and located in the nucleus. Cell. 1992 Oct 30;71(3):515-26.
Do men have the Xist gene?
Meanwhile, strong expression of XIST (which is completely absent in male somatic tissues) has been demonstrated in mature testis; these levels; however, are lower than those found in female somatic tissues [25].
Can Xist affect DNA methylation?
2001), we show that Xist RNA, DNA methylation, and histone hypoacetylation act synergistically to achieve a highly stable inactive state.
Why is XIST necessary?
Xist was initially proven to be indispensable for XCI by targeted mutagenesis and transgenesis in mouse embryonic stem cells (ESCs) and in mice. Deletion of the Xist gene results in skewed inactivation of the wild type X chromosome, indicating that this locus is essential for gene silencing [45,46].
How long is the XIST gene?
16.5 kilobase pairs
The XIST gene plays an essential role in X Chromosome (Chr) inactivation during the early development of female humans. It is believed that the XIST gene, not encoding a protein, functions as an RNA. The XIST cDNA is unusually long, as its full length is reported to be 16.5 kilobase pairs (kb).
Why is xist necessary?
What is the name of the other transcript that xist counteracts?
A recently discovered lncRNA called XACT (X active coating transcript) that is unique to human PSCs, but does not reside in the XIC, may aid in maintaining transcriptional activity of the X chromosome from which it is expressed by counteracting XIST [20,28].
Can xist be activated in males?
This process, termed X-chromosome inactivation, is believed to be triggered by X-inactive specific transcript (Xist) RNA. Here we find that Xist RNA can silence X-linked genes efficiently in females but not in males. Thus, Xist RNA is insufficient to inactivate the X chromosome.
