A genetic mutation transforms a group of ants into so-called parasitic queens

About ten years ago, scientists observing clone ants discovered something strange: although this species is known to have no queen, some ants they posed as queens of the colony, dominate his fellow workers. Are so called queens They had giant wings, eyes and ovaries.

Researchers had long assumed that these ants Relying on other workers for their survival, they acquired these traits one by one, through a series of mutations. But now scientists have discovered that a single “supergene” mutation can convert normal clonal workers from raider ants (Ooceraea biroi) In queen-like parasitic sloths.

“It was a shocking discovery,” he said. Live Science in an email Trible “Buck” by Waring, entomologist, John Harvard Distinguished Science Fellow and lead author of the study in which the results were published. “The clonal raider ant is a queenless species of ant, and winged adult females have never been observed in this species before.”

Pseudo-queens are born with wings that lose in adulthood, but retain scars visible. They are the same size as worker ants, but their indifference general A works such as brood care, foraging and nest defense set them apart in the colony.

The researchers isolated the parasites and discovered that their offspring also had wings, suggesting that the queen’s traits were genetic. They performed analyzes to confirm this observation and discovered a mutation in a “supergene” on chromosome 13.

For them, this mutation it may have been the switch that transformed the clonal robber ants from the “wild type” usually found in nature into a mutant variant of the same species.

“It really is amazingsince parasites differ from wild ones in many characteristics, such as morphology (segmented thorax), anatomy and even behavior,” he said. Daniel Kronauerassociate professor and director of the Social Evolution and Behavior Laboratory Since Rockefeller University of New York.

What we are describing here is a mutant strain very close to its ancestors wild type. So it’s not really a different species, but what could be considered an intermediate form, Kronauer added.

Researchers have observed that future queens they laid twice as many eggs than normal clone ants. However, they cannot let their numbers grow too much, as they need workers. “When they become too common, they run into problems,” Kronauer said. The parasites hook their bulky wings into the skin of the pupae as they molt, and if there aren’t enough workers around to help disentangle them, many of them die.

According to the study, published February 28 in the journal current biology, the optimal point seems to be when the parasites make up about a quarter of the colony. When the proportion of budding queens was higher, their Survival rate they fell.

Although some species of exclusively social parasitic queen ants exist in nature, the cloning ant is the first documented to have developed aspirants within its own species. “I was very surprised to find these ants,” Kronauer said.

And he concluded: “The social parasites they tend to be very rare and are only found in a few colonies of the host species. But the crazy thing about this is that the parasites have to appeared in the host colony by mutation, instead of having infiltrated the colony from the outside, as social parasites do in the wild.

Continue reading: