Insulin inhibition as a fountain of youth for ant queens

Queen ants live long. Sometimes decades longer than their subjects. While the males are granted only a few pleasurable hours to days of life in order to fertilize the queen; the workers remain on earth for a few weeks to months, ant queens reach a Methuselah age of several years to decades.

Now scientists at New York University have identified a protein that may enable the queens to live long lives - it's called imaginal morphogenisis protein-late 2 (Imp-L2) and inhibits insulin, they write in the journal Science.

Most of us know the hormone as a blood sugar regulator. If the body can no longer produce it, the glucose level rises pathologically. The reason: most cells cannot absorb the energy supplier sugar from food without insulin. This is no different with ants. This is why ants also need insulin, especially the queens.

Laying millions of eggs is an extremely strenuous and energy-sapping job. However, there is more to the hormone: insulin influences the life expectancy of flies, mice and probably humans as well in a different way.

The following applies: the higher the insulin level, the shorter the life. If you put mice on a diet, for example, they get significantly older. However, this also means that the life expectancy of animals that use a lot of energy - for example by laying eggs - is shorter than that of their conspecifics, the scientists write in Science.

But the ant queens are an exception. The Indian jumping ant queen studied by the US researchers, Harpegnathos saltator, usually lives for five years, while its workers only an average of seven months.

Unless the queen dies. Then a worker fights for the rank of pseudoqueen and begins to lay eggs. Curiously, their life expectancy then increases to four years. The team led by neurobiologist Claude Desplan discovered that the pseudoqueens now produce more insulin in their brains. This stimulates the formation of ovaries.

These in turn release the insulin-inhibiting protein Imp-L2, which, however, only acts on the metabolic pathway that regulates life expectancy. However, that doesn't mean the pseudo-queen can now be sure of her long life. Once a real queen replaces her, she loses her special status and her fountain of youth dries up. Incidentally, the age record among insects is held by a queen of the black garden ant. She was almost 29 years old.