A kinetosome is a small, cylindrical structure found at the base of cilia and flagella in eukaryotic cells. It acts as a basal body that organizes and anchors these microtubule-based structures, enabling their movement.
What does a Kinetosome do?
- Anchors cilia and flagella: The kinetosome provides a stable base for the microtubules that make up the cilia and flagella, ensuring their proper attachment to the cell.
- Organizes microtubule assembly: It acts as a template for the formation of the axoneme, the core structure of cilia and flagella, which is composed of microtubules arranged in a specific pattern.
- Regulates ciliary and flagellar movement: The kinetosome plays a role in controlling the direction and frequency of ciliary and flagellar beating.
Structure of a Kinetosome
- Microtubule triplets: The kinetosome consists of nine microtubule triplets arranged in a ring, forming a cylindrical structure.
- Central tube: Some kinetosomes also have a central tube that runs through the center of the structure.
- Other components: The kinetosome also contains various proteins, including tubulin, dynein, and nexin, which are involved in microtubule assembly, movement, and stability.
Examples of Kinetosomes in Action
- Cilia in respiratory tract: The cilia lining the respiratory tract use kinetosomes to beat rhythmically, moving mucus and trapped particles out of the lungs.
- Flagella in sperm cells: The flagellum of a sperm cell, powered by a kinetosome, propels the cell towards the egg.
How does a Kinetosome form?
Kinetosomes are formed from centrioles, which are also cylindrical structures made of microtubule triplets. During cell division, centrioles duplicate and one of the new centrioles becomes the kinetosome for the newly formed cilium or flagellum.
