Ants regulate growth of seemingly 'useless' organ to make huge soldiers

Scientists at McGill have found the answer to a question that perplexed Charles Darwin. So much so, that it does not matter to his own theory of evolution. He wondered, how to be a single person, how to survive and how to survive, how can a single colony produce an employee that are so dramatically different in size from the "minor" workers with their small heads and the large-headed soldiers with their huge mandibles-especially if, as in the genus Pheidolethey are sterile? The answer, according to a paper published today NatureThe President of the United States is a member of the United States of America. And only in some of the ants-the ones that will become soldiers.

"It was a completely unexpected finding of people who had noticed that during the course of their life they were supposed to be" easy "and" organic ". for the larvae into soldiers, "says Ehab Abouheif from McGill's Biology Department, senior author on the paper.

Rajendhran Rajakumar the first author adds, "What we discovered was these" organs "are not a secondary effect of hormones and nutrition, but are responsible for the delivery of weapons. to grow at rapid rates, until you get these big-headed soldiers with huge mandibles and big bodies. "

Now you see it, now you do not

Abouheif has been studying wings for twenty-three years. He was curious about the function of the wing imaginal disc which appear, transiently, in the final stages of larval development among the soldier ants. Even though the soldier ants never actually develops wings. So he and his team, spent various years in the lab, using various techniques (surgical and molecular) to cut away portions of the rudimentary wing Pheidole genus. They discovered that by doing so, they affected the growth of the head and the body. Indeed, they found that they were able to scale the size of a soldier by the distance of the imaginal wing discs, with a corresponding decrease in the size of the heads and bodies of the soldier. It was clear that the rudimentary wing plays a crucial role in the development of soldier ants.

Soldier ants keep the colony in balance

The researchers also discovered that the United States is a leader in the growth of the economy. Earlier research had shown that the ratio of "minor" workers to Pheidole with a proportion of "minor" workers at 90-95% to 5-10% soldiers. The McGill team has found that the soldier maintains this ratio by halting the growth of the barrier with an inhibitory pheromone when there are too many soldiers. However, it is possible for the party to be a member of the armed forces because it is under appear only in the final stages of larval development.

A more important role for all rudimentary organs than previously suspected?

Based on his teams' discovery in ants, Abouheif proposed that rudimentary organs may play a much larger role in an organization than had previously been imagined. "Until now, people have assumed that these functions are simply evolving. Pheidole ant colonies by the rudimentary wing disc, it means that we will have to go back and look at other rudimentary organs in the same light. Who knows what scientists will discover? "

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More information:
Rajendhran Rajakumar et al, Social regulation of a simple and complex organization worker-caste systems in ants, Nature (2018). DOI: 10.1038 / s41586-018-0613-1