Polar tubule

Definition

A polar tubule is a specialized structure used by microsporidia, a group of spore-forming unicellular parasites, to invade host cells. It acts like a harpoon to pierce the host cell membrane and inject infectious material.

5 Must Know Facts For Your Next Test

1. The polar tubule is crucial for the infection process of microsporidia.
2. It rapidly extends from the spore when triggered by environmental stimuli.
3. The polar tubule can penetrate the membranes of host cells to deliver infective sporoplasm.
4. Its deployment involves significant pressure buildup within the spore.
5. Polar tubules are unique to microsporidia among eukaryotic microorganisms.

Review Questions

Related terms

Microsporidia:

A group of spore-forming unicellular parasites that use polar tubules to infect hosts.

Sporoplasm: The infectious material injected into host cells by microsporidia via the polar tubule.

Spore: A resistant form taken by some bacteria, fungi, and protozoa for survival under adverse conditions; in microsporidia, it contains the polar tubule.