Which noncoding RNA coats the inactive X-chromosome in regions of heterochromatin?

Question

Question: Which noncoding RNA coats the inactive X-chromosome in regions of heterochromatin?

Options:

1. Xist RNA
2. tRNA
3. HP-1 RNA
4. 5S rRNA

Answer 1

1. Xist RNA

Xist RNA is noncoding RNA coats the inactive X-chromosome in regions of heterochromatin.

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Explanation:

Xist RNA was subsequently found to physically coat the inactive-X chromosome, and studies in mice demonstrated that Xist remains associated with the inactive-X during mitosis.

The presence of Xist on the mitotic inactive-X supports its role as the transmitter of the epigenetic state of the inactive-X from one cell division cycle to the next. In human cells, however, Xist RNA appears to dissociate from the X-chromosome during mitosis.

Source: ncbi.nlm.nih.gov