‘Zombie Ant’ Infected By Fungal Parasite, But Left Its Brain Unharmed

Zombie ant is infected by fungus, yet leaves its brain unharmed.

A new study reveals that a fungal parasite, known as the ” Zombie ant fungus” could infect and take control of the ant’s body without infecting its brain. Then, the fungus enters the ant’s head and releases its fungal spores that could spread throughout the colony. This could take place all over again in ten tormenting days.

The study was published in the journal Proceedings of the National Academy of Sciences. It was led by researchers from the Penn State University, according to Phys. Org.

The ant has been called “Zombie ant” when it is infected by a certain fungus called Ophiocordyceps unilateralis sensu lato or referred to as “Zombie ant fungus.” This fungus surrounds and attacks the muscle fibers of the ant’s body. Then, the fungal cells shape a 3-D network that could collectively control and manipulate the ant’s body and its behavior.

Maridel Fredericksen, the lead author of the study and a former master’s degree in entomology at Penn State University, said that the fungus is known to secrete tissue-specific metabolites and trigger alterations in host gene expression. She further said that the changed host behavior is an extended phenotype of the microbial parasite’s genes that are expressed in the body of its host. However, it is not clear how the fungus coordinates these effects to control the host’s behavior.

The researchers examined this process by experimenting the ants and the said parasite. They infected ants with zombie ant fungus or another fungus to know which cell-level effects are distinct. Afterwards, they created 3D images utilizing scanning electron microscopy to identify the fungal cells in the ants’ bodies, according to New Atlas.

The team also used artificial intelligence and machine learning algorithms to evaluate the images and comprehend the ant and fungus cells. The results showed that the fungus cells had spread in the ants’ bodies up to the head, thorax, abdomen, and legs of the ants. Surprisingly, there were no fungal cells in the brains of the ants.

David Hughes, the senior author of the study, said that normally in animals, the behavior is controlled by the brain sending signals to the muscles. However, the results indicate that the parasite is controlling host behavior peripherally.

Hughes further said that they contemplate that the fungus may be keeping the brain of the ants so they could survive until it executes its final biting behavior, which is a critical time for fungal reproduction. The team also thinks that they need to conduct more studies to identify the role of the brain and how much control the fungus exercises over it, according to Hughes.

[Featured Image by Stana/Thinkstock]