Thekey difference在微核和大核之间micronucleus is the smallernucleusthat contains the germlinegenomeof the ciliateprotozoanswhile macronucleus is the largest nucleus, containing the somatic genome of ciliate protozoans.
Nuclear dimorphism is the phenomenon of having two different types of nuclei within the same cell. It is a special characteristic present in protozoan ciliates and some foraminifera. These two nuclei are the macronucleus and micronucleus. They contain separate genomes. The macronucleus is the larger one that controls the metabolism of the ciliate protozoa while micronucleus is the smaller one that carries out reproductive functions and generates the macronucleus.
Moreover, these organisms cannot reproduce without micronucleus. Thus, micronucleus is responsible for the genetic reorganization that occurs during conjugation or cross-fertilization. Not only that, but micronucleus also gives rises to the macronucleus. However, the genome of micronucleus is transcriptionally silent. In addition to these, micronucleus contains a comparatively small amount of DNA.
What is Macronucleus?
DNA in macronucleus controls the metabolism of the organism. Therefore, it is the centre of metabolic activities of the organism. In fact, macronucleus is responsible for the normal functioning of the cell. Thus, it is the non-reproductive nucleus of ciliate protozoa. Moreover, macronucleus is ellipsoidal in shape, and it is active in transcription. Macronucleus disintegrates during conjugation. But, it reforms from the micronucleus bykaryogamy.
- Ciliate protozoans have both micronucleus and macronucleus.
- Both are present within the same cytoplasm.
- And, they have separate genomes.
- Hence, they both code for hereditary information of the organism.
- Thus, both nuclei are equally important for the survival of the organism.
- Most importantly, the micronucleus gives rise to the macronucleus.
What is the Difference Between Micronucleus and Macronucleus?
The following infographic summarizes the difference between micronucleus and macronucleus.
概括– Micronucleus vs Macronucleus
Ciliates are single-celled eukaryotic organisms that show nuclear dimorphism. They have a micronucleus and a macronucleus. Micronucleus is the reproductive nucleus that contains the germline genome essential for reproduction. In contrast, macronucleus is the non-reproductive nucleus that contains somatic genome essential for all the metabolic and normal functioning of the organism. Furthermore, macronucleus has a comparatively large amount of DNA compared to micronucleus. So, this summarizes the difference between micronucleus and macronucleus.