How does X inactivation occurs?
The inactive X chromosome is silenced by being packaged in such a way , that it has a transcriptionally inactive structure called heterochromatin
It is understood that X chromosome inactivation is a random process , occurring at about the time of gastrulation in the epiblast. The maternal and paternal X chromosome have an equal probability of inactivation.
In the early blastocysts stage , cells independently and randomly inactivate one copy of the chromosome . Inactivation occurs at the cellular level , resulting in a mosaic expression , in which patches of cells have an inactive maternal X chromosome, while others have an inactive paternal chromosome.
This inactivation event is irreversible during the lifetime of the cell. X inactivation is reversed in the female germline , so that all oocytes contain an active X chromosome.
Sequences at the X inactivation centre , present on the X chromosome, control the silencing of the X chromosome.
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X inactivation, also known as lyonization, is a process by which one of the two X chromosomes in female mammals is inactivated to ensure dosage compensation between males and females. It occurs early in embryonic development and involves the random silencing of one X chromosome in each cell. This inactivation is mediated by the XIST gene, which produces a long non-coding RNA that coats the inactive X chromosome, leading to its compaction and transcriptional silencing. The choice of which X chromosome to inactivate is random and occurs independently in each cell, resulting in a mosaic pattern of X chromosome activity across tissues in female mammals.
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When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.
When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.
When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.
When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.
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