Tapeworms infect worker ants, causing their bodies to become more like the queen’s, thereby extending their lifespan several times
Deep in the humid leaf litter of the Lenneberg Forest near Mainz, Germany, the tiny worker ants of Temnothorax nylanderi live surprisingly long lives. Normal worker ants usually only live a short and busy life of one to two years, but worker ants carrying a parasitic tapeworm called Anomotaenia brevis can live several times longer. Instead of dying young, they begin to rival their queen, a king ant that lives up to twenty years.Now, a detailed study published in the journal BMC Genomics reveals how this unusual longevity actually works. Scientists at Johannes Gutenberg University Mainz (JGU) have discovered that tapeworms do more than just make ants sick or weak. Instead, it carefully changes the way the ants’ genes work, adjusting normal body processes so that the workers’ bodies begin to behave like long-lived queens.
Using Royal Biology
To understand how this parasite extends lifespan, an international research team led by Professor Susanne Foitzik from JGU’s Institute of Organic and Molecular Evolution (iomE) brought colonies of forest ants into the laboratory. They divided the ants into three test groups: healthy queens, healthy uninfected workers, and workers carrying the tapeworm parasite.Scientists carefully removed two key parts from the ants: the brain and the fat body. In insects, the fat body is an important tissue in the abdomen that stores energy, manages digestion, handles stress and protects the immune system, working in much the same way as the human liver. The researchers used advanced RNA-sequencing technology to measure which genes were active in these tissues. They also studied genetic data from the tapeworm itself to track its activity and examine whether it was using cunning chemical tricks.The results showed clear differences in the way parasites affect their hosts. Rather than causing general damage, the infection changes the ants’ active genes in a very specific way.“Our genetic analysis shows that infection not only makes the ants sick, but also changes their physiology in a highly targeted way,” says Suzanne Voytske. “At the molecular level, infected worker ants exhibit partly queen-like characteristics.”This shift is most intense in the fat body. The genes active in the infected workers closely matched those of the long-lived queen, particularly in biological systems responsible for digestion, immune protection, stress resistance and aging.“The findings in the fat body suggest that the tapeworm takes advantage of the ants’ existing signaling and metabolic pathways and alters them,” Forzke said.
Quiet brain and slow behavior
While the parasite changes the ant’s body to slow aging, it takes an entirely different path in the brain. In a healthy nest, worker ants build, collect food, care for the young, and protect the colony. However, infected worker bees become very quiet, work much less, and sit in the nest for long periods of time.When the researchers examined the brain tissue, they found that the infected worker ants looked nothing like the queen. Instead, many neuropeptides—signaling chemicals that control social behavior, feeding, and energy levels—and the parts of cells that receive them were downregulated.“The effects of infection are therefore tissue-specific,” explains Giulia Blasi, first author of the study and doctoral researcher at iomE. “In the fat body, we see a shift toward a queen-like metabolic profile. In the brain, by contrast, many signaling pathways related to behavior and activity are suppressed.”
indirect acquisition strategy
At first, scientists wondered whether the tapeworm was making its own mimic chemicals to trick the ants’ brains and bodies directly. Many parasites produce false chemicals that resemble the host’s own signals, tricking the host’s body into doing what the parasite wants.However, genetic testing of the tapeworm showed that its chemicals are not similar enough to those of ants to serve as a direct imitator.“The data suggest that the parasite affects the ants indirectly by interfering with the host’s own regulatory networks that control processes such as metabolism, the immune system, aging and behavior,” Brasi said.This ingenious method fits the tapeworm’s life plan. For Anomotaenia brevis, worker ants are just a temporary home. This parasite cannot lay eggs inside ants; its entire life cycle can only be completed in the belly of its primary host, the woodpecker.Making the host ant live longer while making it slow and lazy is a real purpose. An ant can live in a nest for many years without burning itself, providing the tapeworm with a safe, stable home. Meanwhile, as woodpeckers break open their nests in search of snacks, the slowly resting ants have easy access to food.
Gain a clear understanding of how aging occurs
The study, funded by the German Research Foundation, was conducted by JGU researchers Susanne Foitzik, Giulia Blasi and Katharina Schwolow and Hugo Darras from Zhejiang University in Hangzhou, China.These findings provide scientists with a useful natural context to study how aging is controlled at the genetic level. Because worker ants and queens are born with the exact same genetic instructions, their vastly different lifespans depend entirely on which genes are turned on or off.“Queens and workers of social insects have the same genetic base but very different lifestyles and lifespans,” says Susanne Foitzik. “The fact that infected worker ants exhibit molecular signatures in their fat bodies that partially resemble those of the queen suggests that the parasite exploits the ants’ existing biological programs.”The research was conducted by Giulia Blasi, Katharina Schwolow, Hugo Darras and Susanne Foitzik from Johannes Gutenberg University Mainz. Their research is titled Tapeworm infection is associated with transcriptional changes in neuropeptide signaling and caste-specific aging pathways in social insects, Study how parasitic infection affects gene activity and aging pathways in social insects.
