Difference Between Micronucleus and Macronucleus

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.

内容

1.Overview and Key Difference
2.What is Micronucleus
3.What is Macronucleus
4.微核和大核之间的相似性
5.并排比较 - 表格形式的微核与大核
6.概括

什么是微核？

微核是在纤毛原生动物中看到的两个核中较小的核。它包含生物体的种系遗传物质。因此，它控制着生物体的生殖功能。

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?

大核是纤毛原生动物中存在的较大核。它包含具有生物体遗传信息的体细胞基因组。与微核相比，大核由数百至数千个染色体中的DNA组成。

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.

微核和大核之间有什么相似之处？

• 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.
• 此外，他们控制单独的细胞过程。
• Most importantly, the micronucleus gives rise to the macronucleus.

What is the Difference Between Micronucleus and Macronucleus?

纤毛有两个核作为微核和大核。微核是较小的核和生殖核。相反，大核是较大的核和非生殖核。因此，这是微核和大核之间的关键区别。微核基因组是二倍体，而大核基因组是多倍体。此外，微核包含少量DNA，而大核包含大量DNA。因此，这也是微核和大核之间的差异。

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.

Reference:

1. “What Is a Paramecium?” LiveScience, Purch,Available here.
2. “Nuclear Dimorphism.” Wikipedia, Wikimedia Foundation, 31 May 2019,Available here.

Image Courtesy:

1. “Ciliate” By Ali Zifan – Own work(CC BY-SA 4.0)viaCommons Wikimedia
2. “Gastronauta clatratus – 400x – Macronucleus & Micronucleus” ByPicturepest（CC由2.0）viaFlickr