Why Does The Queen Ant Live Five Times Longer Than The Workers?

Why Does The Queen Ant Live Five Times Longer Than The Workers?

Queen Ants Live For Many Years, While Workers Live Only A Few Months. Scientists Have Recently Discovered A Possible Reason For This.

The workers of one species of ant engage in a brutal all-out battle to succeed the queen who has just died, and the winning gets the throne and long life.

After the queen’s death, Indian jumping ants ( Harpegnathos saltator ) fight to determine which worker ant will take the queen’s place. Winning doesn’t just mean producing lots of eggs. And it means living five times as long as the average worker. Now scientists may have discovered how surrogate queens slow down the aging process.

In general, the hormone insulin helps move sugar from the bloodstream into the cells, where the sugar can be used as fuel. The surrogate queens, known as pseudo-queens or gamergates (referring to the Greek words for married workers and not to the GamerGate internet campaign launched against sexual harassment during online video games), must increase insulin production to cope with the enormous amount of food they must consume.

To manage, “If you want to produce eggs, you need a lot of insulin because you’re constantly eating,” Claude Display, one of the paper’s authors and a professor of biology and neuroscience at NYU, told LiveScience.

But theoretically, this rush of insulin must be accompanied by a problem. In addition to helping to transport sugar to cells, insulin initiates several molecular chain reactions, some of which play a role in the aging process.

In particular, the Akt signaling pathway, which is involved in many cellular functions from metabolism to cell survival, can be activated by insulin and has long been associated with aging and age-related diseases.

So, if the pseudo-queen starts pumping out large amounts of insulin, it should theoretically age faster than the average worker ant, which doesn’t produce many hormones. “But with this ant, it’s the exact opposite,” Display said.

The average lifespan of a typical worker ant is about eight months, while pseudo-queens can live about three years and three months. The exciting thing, Display said, is that if the pseudo queen is placed in another colony with an established ruler, it will become an average worker ant.

The lifespan of these pseudo-queens that become workers again (returned workers) is similar to that of workers. Somehow, only the queens and pseudo-queens manage to survive for years despite the abundant insulin they produce.

Display collaborated with his longtime colleague Danny Reinberg, biochemistry and molecular pharmacology professor at New York University School of Medicine, to resolve this apparent paradox.

Their team sampled tissue from regular worker ants, retrograde workers, and pseudoqueens, focusing on tissues involved in metabolism and reproduction. These tissues included brain tissue, ovaries, fat bodies (an organ similar to the human liver), and adipose tissue. The team analyzed which proteins were produced in the sampled tissues using a technique called bulk RNA sequencing.

The RNA molecule, a molecule similar to DNA, carries the genetic instructions on how to make proteins and transfers these patterns from the center of the cell to one of the protein-making sites in the cell.

By examining these RNA instructions, the team discovered that pseudoqueens produced much more insulin in the brain than workers, reverted workers, and began to have more fat and vitellogenin (a precursor to egg yolk) in the fat bodies.

Some of these resources were transferred from the fat bodies to the ovaries to support the ovaries. They used some of the fat to produce a unique pheromone that only queens and pseudo-queens produce (the disappearance of this pheromone in the nest causes the worker ants to leave the nest with fight together).

As the pseudoqueens produce more insulin, their ovaries develop to accommodate the eggs. Insulin drives this process of ovarian maturation through the MAPK signaling pathway, another chain of chemical reactions that can be initiated by insulin.

 Meanwhile, the ovaries produce Imp-L2, which essentially inhibits the Akt signaling pathway, which, when activated, causes rapid senescence of the pseudoqueens.

According to the researchers, Imp-L2 secreted by the ovaries also finds its way into fat bodies, providing an antiaging shield for that organ. The two main branches of the insulin signaling pathway (MAPK and Akt) appear to regulate fertility and lifespan differently, with increased signaling favoring the reproduction of pseudoqueens and decreased signaling in the other, Reinberg said. The increase in their lifespan is consistent.

The Display said the team’s next step is understanding how Imp-L2 inhibits only the aging-related pathway and not the reproduction-related pathway. They plan to study the effects of this insulin-inhibiting protein in other insects such as fruit flies and mammals. “We don’t know what’s going to happen,” Display said. Flies and ants are not exactly alike.

“Even more difficult is predicting whether the antiaging benefits of Imp-L2 for Indian jumping ants will also be seen in non-insect organisms, such as mammals.”