What is difference between heterochromatin and euchromatin?

Heterochromatin is defined as the area of the chromosome which is darkly stained with a DNA specific stain and is in comparatively condensed form. Euchromatin is defined as the area of the chromosome which is rich in gene concentration and actively participates in the transcription process.

What does the presence of euchromatin or heterochromatin indicates?

Euchromatin is a form of chromatin that is lightly packed—as opposed to heterochromatin, which is densely packed. The presence of euchromatin usually reflects that cells are transcriptionally active, i.e. they are actively transcribing DNA to mRNA.

What are the functions of heterochromatin and euchromatin?

Heterochromatin maintains the structural integrity of the genome and allows the regulation of gene expression. Euchromatin allows the genes to be transcribed and variation to occur within the genes.

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 main function of heterochromatin?

A crucial function of heterochromatin, which is generally more compact than euchromatin, is to prevent such selfish sequences from producing genetic instability. Additional heterochromatin roles include asserting cell-type-specific transcription and centromere function.

What is heterochromatin and its function?

Heterochromatin has been associated with several functions, from gene regulation to the protection of chromosome integrity; some of these roles can be attributed to the dense packing of DNA, which makes it less accessible to protein factors that usually bind DNA or its associated factors.

What is the function of constitutive heterochromatin?

Constitutive heterochromatin on highly repeated sequences contributes to genomic stability by suppressing recombination. The centromeric and telomeric repeats are two prominent structural parts of the chromosomes that have specific pathways of chromatin modification.

What is meant by heterochromatin?

Heterochromatin: A genetically inactive part of the genome. Heterochromatin was so named because its chromosomal material (chromatin) stains more darkly throughout the cell cycle than most chromosomal material (euchromatin).

Where is heterochromatin found in the body?

In metazoa, clusters of repetitive DNA are packaged into heterochromatin at the centromere region (Figure 1a, b). Typically, heterochromatin forms at pericentromeric (near the cellular centromere) and telomere regions that comprise repetitive DNA sequences (Bühler and Gasser 2009).

Why is it called heterochromatin?

Emil Heitz (1928) historically identified heterochromatin as the nuclear material that remains highly condensed within the interphase nucleus. He named these regions ‘heterochromatin’ to distinguish them from the regions showing variable staining and condensation, which he called ‘euchromatin’.

What’s the difference between an euchromatin and a hetero chromatin?

Darker staining indicates tighter DNA packaging. Heterochromatins thus have tighter DNA packaging than euchromatins. Heterochromatins are compactly coiled regions while euchromatins are loosely coiled regions. Euchromatin contains less DNA while heterochromatin contains more DNA.

• Heterochromatin is of two types, but euchromatin is present in only one form. • Heterochromatin is easily and highly stained but not euchromatin. • Euchromatin is highly active but heterochromatin is not. • Heterochromatin is found at the periphery of the nucleus while euchromatin is present in the inner body of the nucleus.

How is heterochromatin related to structural integrity?

Heterochromatin is involved in maintenance of structural integrity and regulation of gene expression. Regions of euchromatin are non sticky. The areas of heterochromatin are quite sticky. Euchromatin is genetically active. It may also be exposed to chromosomal cross over.

How is heterochromatin related to the gene regulating mechanism?

The gene regulating mechanism is the process of transforming euchromatin into heterochromatin or vice versa. The active genes present in euchromatin gets transcribed to make mRNA whereby further encoding the functional proteins is the main function of euchromatin. Hence they are considered as genetically and transcriptionally active.