Here's a breakdown of how Ophiocordyceps unilateralis hijacks the nervous system of flies:
1. Spore Attachment: The spores of Ophiocordyceps unilateralis attach to the body of the fly.
2. Germination and Penetration: The spores germinate and penetrate the fly's cuticle, usually through a natural opening such as a spiracle (a small opening used for respiration).
3. Fungal Growth: Once inside the fly's body, the fungus begins to grow and develop hyphae, which are thread-like structures that spread throughout the fly's body.
4. Neuroinvasion: The hyphae target the fly's nervous system, particularly the brain and central ganglia. The fungus invades and manipulates the fly's nervous tissue.
5. Behavioral Changes: The fungus starts producing chemical compounds and neurotransmitters that interfere with the fly's normal behavior. This leads to changes in movement patterns, such as reduced mobility, increased activity, or altered walking behavior.
6. Host Manipulation: As the fungus gains more control over the nervous system, it manipulates the fly's behavior to its advantage. For example, the fungus may drive the fly to climb to a high location, such as a plant stem or a twig. This behavior helps disperse the fungus's spores and facilitates its transmission to other hosts.
7. Host Death and Fungal Growth: Eventually, the fungus kills the fly as it consumes the fly's tissues and nutrients. The fly's body serves as a nutrient source for the fungus, allowing it to grow and develop further.
8. Fruiting Body Production: The fungus produces fruiting bodies, which are mushroom-like structures that emerge from the dead fly's body. These fruiting bodies release new spores, completing the parasitic life cycle and infecting more flies.
It's important to note that the exact mechanisms and effects of Ophiocordyceps unilateralis may vary depending on the specific species of fungus and the host insect it infects. The host manipulation strategies may differ, and the progression of infection may vary in duration.
