Difference Between Centriole and Centrosome

Main Difference – Centriole vs Centrosome

Centriole in the centrosome is involved in the formation of spindle apparatus during the cell division. The centriole is made up of tubulin proteins assembled in a cylinder like a cartwheel structure. The mother and the daughter centrioles come together to form the centrosome. The centrosome is responsible for the formation of the spindle apparatus during the cell division. The main difference between centriole and centrosome is that centriole is the microtubule unit which forms the centrosome whereas centrosome is an organelle in the cytoplasm which is made up of two centrioles.

This article looks at,

1. What is a Centriole
      – Structure, Function, Characteristics
2. What is a Centrosome
      – Structure, Function, Characteristics
3. What is the difference between Centriole and Centrosome

What is a Centriole

A centriole is a cylindrical structure, assembled of two centrioles – mother and daughter centrioles – in an orthogonal manner to form the centrosome. A centriole is made up of nine triplet microtubules assembled in a cylinder-like structure. Centrin, cenexin and tektin are the types of microtubules which are arranged in this cylindrical structure to form the centrioles. Centrioles form aster during the interphase and spindle apparatus during cell division. The structure of the two centrioles forming the centrosome is shown in figure 1.

Figure 1: Mother and Daughter Centrioles in a Centrosome

Function of Centriole

Centrioles organize microtubules in the cytoplasm in order to form the spindle apparatus during the cell division. The position of the centrioles in the cytoplasm determines the plane the nuclear division is going to take. The mother centriole positions the flagella and cilia in the non-dividing cells by becoming the basal body. Sperm centrioles are involved in either the movement of sperms by forming the sperm flagellum or the development of embryo after the fertilization. The non-functional cilia and flagellum in a cell cause both developmental and genetic diseases like Meckel-Gruber syndrome.

What is a Centrosome

A centrosome is an organelle which serves as the organizing center of all microtubules in the animal cell. It is composed of two centrioles arranged in an orthogonal manner. The two centrioles are surrounded by pericentriolar material (PCM). The PCM is an amorphous mass, anchoring microtubules by microtubule nucleation. The anchoring microtubule types are γ-tubulina, ninein, and pericentrin. Centrosomes are only involved in the metazoan lineage of eukaryotes. Thus, plant and fungal cells lack centrosomes. Plant cell spindle is formed independently, without the control of centrosomes.

Centrosome Cycle

The centrosome is usually attached to the plasma membrane. During the prophase of the cell division, centrosome duplicates, forming two centrosomes. These two centrosomes move to the opposite poles of the cell. After the degradation of the nuclear membrane, each centrosome nucleates their microtubules in order to form the spindle apparatus. The spindle microtubules are later attached to the centromeres of each chromosome in the cell. Contractions of the spindle microtubules let the chromosomes segregate into opposite poles of the cell, creating new, two daughter cells. After the division of cytoplasm, each formed daughter cells contains a single centrosome. The complete centrosome cycle is described in figure 2.

Figure 2: Centrosome cycle

Difference Between Centriole and Centrosome

Definition

Centriole: A centriole is the microtubule unit which makes the centrosome.

Centrosome: A centrosome is made up of two centrioles.

Structure

Centriole: Centrin, cenexin, and tektin are the types of microtubules arranged in this cylindrical structure to form the centrioles.

Centrosome: Centrosome contains two centrioles arranged in an orthogonal manner.

Function

Centriole: Mother centriole forms flagella and cilia in non-dividing cells.

Centrosome: The centrosome forms spindle apparatus during the cell division.

Conclusion

Centriole and centrosome are two components of a metazoan cell, which are mainly involved in the cell division. A centrosome is made up of two centrioles which are arranged in an orthogonal manner. A centriole is made up of centrin, cenexin and tektin like tubulin proteins. Nine triplet microtubules are assembled in a cylinder like a cartwheel structure to form a centriole. The two centrioles are surrounded by PCM which is an amorphous mass. The centrosome anchors microtubules in the cytoplasm by a process called microtubule nucleation. The anchoring microtubule types are γ-tubulina, ninein, and pericentrin, involved in the formation of spindle apparatus.

Reference:
1.”Centriole.” Wikipedia. Wikimedia Foundation, 12 Mar. 2017. Web. 13 Mar. 2017.
2.”Centrosome.” Wikipedia. Wikimedia Foundation, 06 Mar. 2017. Web. 13 Mar. 2017.

Image Courtesy:
1. “Centriole-en” By Kelvinsong – Own work (CC BY 3.0) via Commons Wikimedia
2. “Centrosome Cycle-rawtext”By Kelvinsong – Own work (CC BY-SA 4.0) via Commons Wikimedia