AN OVERVIEW ON CENTROSOMES

The centrosome is an organelle in cell biology that functions as the animal cell’s principal microtubule-organising centre (MTOC) and a cell-cycle regulator. In animal cells, the centrosome is remarkably similar to DNA. Each daughter cell receives one centrosome from the parent cell during cell division. The mitotic spindles are organised by the newly generated centrosomes. Let’s learn more about this and improve our knowledge. Let’s start!

WHAT IS A CENTROSOME?

The centrosome is an organelle in cell biology that functions as the animal cell’s principal microtubule-organising centre (MTOC) and a cell-cycle regulator. The centrosome is found in the eukaryotic cells. The pericentriolar material 

(PCM) surrounds the centrosome, which is made up of two centrioles and an electron-dense matrix. The Pericentriolar materiaL PCM comprises proteins such as -tubulin, pericentrin, and ninein, which are involved in microtubule nucleation and anchoring. During cellular differentiation, a cilium takes the role of the centrosome in many cell types. The cilium, however, is replaced by the centrosome once the cell begins to divide. 

THERE ARE FOUR PHASES IN THE CENTROSOME CYCLE :

1.G1 PHASE – The G1 phase is when the centrosome is duplicated.

2. G2 PHASE -The centrosome maturation occurs during the G2 phase.
3. THE MITOTIC PHASE – The centrosome separation occurs during the mitotic phase.
4. THE LATE MITOTIC PHASE – The chromosomal disorientation phase occurs late in the mitotic cycle.

STRUCTURE OF CENTROSOME

The centrosome consists of two centrioles that are perpendicular to each other. It consists of a daughter centriole, and a mother centriole, which is connected by interconnecting fibres. It is made up of a protein complex that aids in the production of new microtubules. An amorphous pericentriolar matrix surrounds the centrioles. It plays a role in cytoplasmic microtubule nucleation and anchoring.

In animal cells, the centrosome is remarkably similar to DNA. Each daughter cell receives one centrosome from the parent cell during cell division. The mitotic spindles are organised by the newly generated centrosomes.

CENTROSOME IN ANIMAL CELL

Centrosomes are not essential for cell division in most mammalian cells, despite the fact that they improve the efficiency of the mitotic spindle arrangement. Centrosome malfunction can induce cancer in humans due to an increase in chromosomal instability or cancer cells’ capacity to spread through the bloodstream.

CENTROSOME IN PLANT CELL

The plants and fungi lack centrosomes, they rely on MTOC structures to keep their microtubules in order. Except in flagellated male gametes, which are found in some flowering plants, plant cells lack spindle pole bodies and centrioles (conifers). The nuclear envelope appears to take up the MTOC’s principal function of spindle organisation and microtubule nucleation during plant cell mitosis. Higher plants have created a unique mechanism to control the cytoskeleton’s dynamics and assembly. In many other eukaryotes that are pledged to establishing polarity, microtubules are nucleated in organising and nucleation centres. Plants do not have centrosomes that resemble organelles, but they are capable of forming spindles and have created cytoskeletal arrays such as the preprophase band, cortical arrays, and phragmoplast that participate in essential growth processes.

FUNCTION OF CENTROSOME:

In the following subtopic we will go through the function of centrosome:

• Centrosomes are involved in cell division. 
• The centrosome keeps track of the chromosome number during cell division.
• Phagocytosis also stimulates changes in the morphology of the cell membrane.
• The centrosome aids in the organisation of microtubules during mitosis, ensuring that centrosomes are dispersed to each daughter cell.
• The centrosome controls microtubule and cytoskeletal structure mobility, allowing for changes in the form of animal cell membranes.
• They control microtubule and cytoskeletal structure mobility, allowing for changes in the form of animal cell membranes.
• Microtubules give rise to flagella and cilia. Flagella and cilia play an important role in embryonic development, sensation, signal transmission, and motility during various developmental and cellular processes.
• Because they include regulatory complexes such as checkpoint proteins and tumour suppressors, centrosomes function as a signalling platform. The centrosome can also control the cell cycle by controlling the G1-S transition and cytokinesis, as has been suggested.

CONCLUSION:

From the above article, we got to know about centrosomes. The centrosome is an organelle in cell biology that functions as the animal cell’s principal microtubule-organising centre (MTOC) and a cell-cycle regulator. There are four stages involved in the development of the centrosome.  Cancer is caused by centrosome amplification. According to Boveri’s theory, aneuploidy caused by centrosome amplification causes tumours. They control microtubule and cytoskeletal structure mobility, allowing for changes in the form of animal cell membranes.