What is the difference between facultative heterochromatin and constitutive heterochromatin?
Both are very similar but the two main differences that distinguish them are that constitutive heterochromatin is stable and has satellite DNA, while facultative heterochromatin is reversible and has LINE sequences.
What are the two types of heterochromatin and how do they differ?
There are two types of heterochromatin, constitutive HC and facultative HC, which differ slightly, depending on the DNA that they contain. The richness in satellite DNA determines the permanent or reversible nature of the heterochromatin, its polymorphism and its staining properties.
What is the function of facultative heterochromatin?
The Latin word “facultas” literally means “opportunity.” Facultative heterochromatin (fHC) then designates genomic regions in the nucleus of a eukaryotic cell that have the opportunity to adopt open or compact conformations within temporal and spatial contexts.
Where is the facultative heterochromatin?
interphase nucleus
Heterochromatin pertains to the darkly stained regions of the chromatin in the interphase nucleus.
What’s the difference between constitutive and facultative?
The main difference between constitutive and facultative heterochromatin is that constitutive heterochromatin is a permanent factor in a particular cell type, whereas facultative heterochromatin is not a permanent character of each cell of particular cell type.
What is the difference between constitutive and facultative genes?
Constitutive heterochromatin contains genes that are stably repressed, whereas facultative heterochromatin retains the ability to convert between states.
What is facultative chromatin?
Facultative heterochromatin: Chromosome material that can be either heterochromatin or euchromatin. The inactive X chromosome is made up of facultative heterochromatin. When a woman transmits that X chromosome to a son, the chromosome reverts to the euchromatic state and to genetic activity.
Which one of the following is an example of facultative heterochromatin?
An example of facultative heterochromatin is X chromosome inactivation in female mammals: one X chromosome is packaged as facultative heterochromatin and silenced, while the other X chromosome is packaged as euchromatin and expressed.
Is the centromere facultative heterochromatin?
Constitutive heterochromatin is present at fixed locations on chromosomes: as in centromere. Compared to this, facultative heterochromatin is in temporarily inactivated functional state as in case of one of the two X chromosomes present in cells of females.
What is constitutive and facultative?
What is a facultative heterochromatin?
Facultative heterochromatin is the result of genes that are silenced through a mechanism such as histone deacetylation or Piwi-interacting RNA (piRNA) through RNAi. It is not repetitive and shares the compact structure of constitutive heterochromatin.
