We use cookies to improve your experience and understand how Examtube is used. You can accept analytics cookies or continue with essential cookies only.
Privacy policy4 public questions tagged with this topic.
The XIST gene is responsible for X chromosome inactivation in female mammals.
Ref: NCERT Class 12 Biology Chapter 4: Principles of Inheritance and Variation Mendel's Laws - Dominance Segregation Independent Assortment
Dosage compensation in female mammals equalizes X-linked gene expression relative to XY males. One X chromosome randomly inactivates early embryogenesis through coating by XIST long noncoding RNA expressed from inactive X, recruitment of Polycomb repressive complex 2 depositing H3K27 trimethylation, H2A K119 ubiquitination, promoter DNA methylation and late replication shift. Condensed inactive X persists as heterochromatic Barr body at nuclear periphery in interphase somatic nuclei, detectable in buccal smears or neutrophil drumsticks. It remains transcriptionally silent except pseudoautosomal regions escaping inactivation, reflecting epigenetic silencing not Y-related.
Ref: Mary Lyon Hypothesis 1961; Lodish et al., Molecular Cell Biology, 9th ed., Chapter 8: Barr Body Inactive X Chromosome
This page is supported by advertisements. An ad blocker is stopping those ads from loading, so we cannot show the rest of the page yet. Pause the blocker for this site, then continue. We will check again automatically.
You can keep using this site after advertisements are allowed to load.
