To turn an ant into an obedient zombie parasitic fungus Cordyceps violates his circadian rhythms, the system of perception of odours and the transmission of neurotransmitters. As a result, the insect leaves the nest, raised to the appropriate plant and hanging it to death. This allows the fungus to get into the optimal place to spread spores. To describe the manipulation of Cordyceps on the molecular-genetic level have been the authors of an article published in the journal G3: Genes, Genomes, Genetics.
Many parasites skilfully manipulate the behavior of the host to increase its chances of survival and procreation. For example, some types of Cordyceps fungi of the genus Ophiocordyceps – infected ants are forced to leave the colony, to climb on the plant and hang on it, being held by the jaws. After the death of the insect from it grows a fruit body of a mushroom. In fact, Cordyceps makes the host vehicle to move to a place that is perfect from the point of view of maturation and spore distribution.
Dramatic relationships of Cordyceps and ants became widely known not only among biologists but also in popular culture. Nevertheless, scientists still don’t know exactly how the fungus controls the behavior of the owner.
The researchers, led by will and Ian (Ian Will) from the University of Central Florida decided to consider this issue at the molecular-genetic level. They focused their attention on the Cordyceps sinensis O. camponoti-floridani and its specific host, the ant, the carpenter Camponotus floridanus. Insect infected by spores of the fungus and tested it, as this will affect the gene activity of both species. To do this, scientists conducted three sequencing RNA of the parasite and the host, before infection, after infection and after the death of the ant.
The analysis identified a number of candidate genes, which allows the Cordyceps to produce toxins, enzymes and secondary metabolites to control the behavior of the owner. Similarly, the genome of the ant was isolated genes that serve as targets for parasite.
The researchers showed that the fungus strikes on several important functions of the nervous system of the host. For example, he knocks the ant’s mode of the day, breaking work associated with circadian rhythm genes. Even more devastating parasite affects the victim’s sense of smell, the main channel of communication with relatives. In the result, the infected individual loses contact with the colony, far away from her and not returned on time. Additional impact of intervention of Cordyceps in the transmission of neurotransmitters.
At the last stage the obtained data are compared with the results of similar studies conducted with a different pair of host-parasite — kimflemingiae O. and C. castaneus. It turned out that the relationship of different types of Cordyceps and ants are quite similar from a molecular genetic point of view. Perhaps parasitic fungi have acquired the ability to brainwash the ants once and then adjust it to a specific species.
The Cordyceps is not the only parasites are able to manipulate the behavior of hosts. Today, scientists know that this trait is widespread in nature. To learn more about the creatures that turn their victims into real zombies, from our test, “Resident evil”.
Sergey Knee High