Science

Scary fungus manipulates 'zombie ants' to control muscles without invading the brain

In some horror novels and television dramas, what zombies, zombies, then we have seen no surprise. Perhaps we think that these things will not come true, but in nature, there are things that spread in a way that will make people look at the back of the chill, such as some fungus parasitic in the body of ants, ants directly into no autonomous consciousness of the zombie - zombie ants. A new study has revealed how this fungus "controls" the process of ants.

Scary fungus manipulates 'zombie ants' to control muscles without invading the brain

The fungus most studied by scientists is a genus of Ophiocordyceps. After being infected by Ophiocordyceps, the worker ants are instructed to leave the anthill and climb to higher ground, then bite down on something with their jaws and die. Previous studies have suggested that the fungus controls the ants' brains, allowing them to make their final "death bite. The latest research suggests that they do not need to invade the brain, but directly control the muscles to do so!

Scary fungus manipulates 'zombie ants' to control muscles without invading the brain

A team led by biologists David Hughes and Colleen Mangold from the Pennsylvania State University in the United States proved this. In the report, the fungal spores infect the ants at different stages of infection, starting with the exoskeleton and gradually infiltrating the internal soft tissues where they have nutrients. The spores then begin to grow budding tubes and hyphae inside the ant's body to create a network of mycelium that penetrates its muscles.

Scary fungus manipulates 'zombie ants' to control muscles without invading the brainScary fungus manipulates 'zombie ants' to control muscles without invading the brain

The team found that the mycelial network only controlled muscle fibers throughout the body of the zombie ants, destroying encapsulated muscle fibers, but did not invade the brain, and the neuromuscular junction (the intersection of nerves and muscles) was not affected. At the same time, the fungus of the genus Serpentis can cause the muscles of the ant's jaws to contract before death with such force that the muscle fibers are severely damaged, making it impossible for the ant to relax. The fungus then grows an antenna-like stem on the ant's head, spreading spores to the leaves and nearby soil, depending on which unlucky ant passes below and becomes infected.

Scary fungus manipulates 'zombie ants' to control muscles without invading the brain

The team said it is not clear why the fungus senses that the zombie ants are ready to bite branches, but it is assumed that the fungus will bite branches at the moment of zombie ants, synchronized secretion of an unknown substance, force the jaw muscles to contract, and eventually become a natural fungal spore disperser. The team also found some unknown "bead-like structures" in the zombie ants' bodies, which are unknown whether they belong to the fungus itself or the substances released by the ants' bodies.

In fact, parasitic and symbiotic behavior in nature is very common, but the emergence of such complex manipulation behavior is still quite rare. But ants are not the only unlucky ones, as many insects and frog amphibians have suffered from them. For example, the frog pot fungus can turn northeastern rain frogs into "sex zombies," and northeastern rain frogs become more attractive with faster and longer courtship calls after being infected with the frog pot fungus. According to fossil studies, this type of fungal transmission has been going on for nearly 50 million years, and perhaps there are countless fungal hosts throughout the world.