Question

Difference between heterochromatin and euchromatin?

Answer 1

Our body is composed of billions of cells. A typical cell contains a nucleus, and the nucleus contains chromatin. According to biochemists, the operational definition of chromatin is the DNA, protein, RNA complex extracted from eukaryotic lysed interphase nuclei. According to them, the chromatin is the product formed from the packaged special proteins commonly known as histones. To put it simply, the chromatin is primarily the combination of deoxyribonucleic acid or simply DNA and other types of protein. Chromatin is the one responsible for packaging DNA into smaller volumes so that they can fit inside the cell. It is also responsible for strengthening the DNA for mitosis and meiosis to take place. Chromatin also prevents damaging the DNA and controls the gene expression and replication of the DNA.
here are two varieties of chromatin. They are euchromatin and heterochromatin. These two forms are distinguished in a cytological manner dealing with how intensely each form is stained. The euchromatin is less intense than heterochromatin. This only indicates that heterochromatin has tighter DNA packaging.
Difference # Euchromatin:
1. The chromatin fibres in this region are loosely coiled as compared with hetero¬ chromatic regions
2. Euchromatin is deeply stained in divisional cycle but less stained in interphase.
3. The region is genetically active and con¬tains unique DNA.
4. Euchromatic regions are able to synthesize mRNA in vitro.
5. Euchromatic regions are seen to their DNA earlier than heterochromatin. They replicate during ‘S’ phase.
6. Due to addition or loss of this region phenotype is affected.
7. This region is not sticky.
8. The crossover frequency is more in euchro¬matin.
9. Euchromatin does not show heteropycnosis.
10. Euchromatin is less affected than hetero chromatin by temperature, sex, age, etc.
Difference # Heterochromatin:

1. The chromatin fibres in this region are more tightly folded than euchromatic regions.

2. Heterochromatin is deeply stained in interphase but less stained in divisional cycle.

3. Heterochromatic regions are unable to synthe¬size mRNA in vitro.

4. Heterochromatic regions are unable to synthe¬size mRNA in vitro size mRNA in vitro.

5. Heterochromatic regions are seen to replicate during the onset of divisional cycle.

6. Addition or loss of this region does not affect phenotype.

7. This region is sticky.

8. Crossover frequency is less than euchromatin.

9. Heterochromatin shows heteropycnosis.

10. Heterochromatin is more affected than euchro¬matin by temperature, sex, age of parents, proximity to the centromere.