Survival of parasitic fungus Ophiocordyceps unilateralis

The researchers found that a species of Ophiocordyceps unilateralis, which has a unique breeding method when using ants, forces ants to change behavior, not control the insect's nervous system. Instead, fungi invade and control ants' muscles.

This mushroom is found in the tropical forests of Brazil. The penetrating species. When ant colonies were infected with fungal spores, ants climbed the tree at a height of about 25cm above the ground (where the temperature and humidity are optimal for the growth of fungi), clinging the jaw to the petiole and dying.

After a while, the body of the fungus develops from the ants and the stem end of the fungus spores. When the other ants climbed the tree along the line of the cousins' foraging food, the spores fell again, infecting new ants.

Mushroom ants Polyrhachis armata - (Photo: Bernard DUPONT / Flickr).

Entomologist David Hughes of the University of Pennsylvania, USA, studied the interaction of parasitic fungi with ants for years to explore the mechanism that allows parasitic fungi to turn prey into a tool. harm. His colleague Maridel Frederiksen obtained very thin slices of ants infected with parasitic fungi with a thickness of only 50 nanometers, which is thinner than a human hair a thousand times.

Discovered under a microscope a cut, the researchers modeled three-dimensional models of ants to observe the spread of fungal spores inside the ants. To describe only one insect's muscle in this way takes a month. In order to accelerate the work, scientists turned to the help of computer technology expert Danny Chen, who trained computer networks to distinguish fungal cells from ant cells.

It turns out, fungal cells swim in hemolymph at first (a fluid in the circulatory system of arthropods, similar to blood and fluid between cells) of ants and reproduce in them. At a certain point, they begin to merge, forming a complete body. It has the form of a network of tiny tubes. They penetrate muscle cells or enter space between ants' muscle cells.

As a result, all of the ant muscle fibers are entangled in a network of fungal cells . It is particularly interesting that the fungus invades the entire ant body, including the head, but the fibers of the fungus do not affect the cells in the head - the brain of the insect. This means that fungi control ant behavior completely through the impact of ants' muscles.

The research results are published in Proceedings of Sciences.