Long Live The Queen...Ants

Doireann Hockel

Recent studies have shown that queen ants have found a way to extend their life by blocking part of a molecular pathway linked to ageing. Animals such as ants should not live as long as they do because the energy these animals put into reproduction, which is a heavy focus for ants, takes time off the end of their lives. Nonetheless, queen ants produce millions of eggs and live an extraordinarily long time compared with worker ants that don’t reproduce. When queens of the species Harpegnathos saltator gear up to reproduce, a part of the insulin signalling pathway gets blocked. This molecular pathway has long been implicated in ageing in mammals, including humans. The result of this is that some ant species have queens that survive up to 30 times as long as their workers, whilst continuing to reproduce on large scales.

As if this wasn’t strange enough, when a Queen of the Harpegnathos saltator species dies, ordinary female worker ants get ready for a duel to replace her and begin a transformation into what is known as the ‘gamergate’ form. They develop ovaries, start laying eggs and transition into gamergates. When a worker transitions into a gamergate, her life span becomes five times as long as it was originally for the duration of the competition. But if she doesn’t end up becoming queen and reverts back to a worker, her life span shortens again.

H. saltator gamergates extend their life spans by taking advantage of a split in the insulin signalling pathway, which is the chain of chemical reactions that drive insulin’s effects on the body. One branch of this pathway is involved with reproduction, while the other is implicated in ageing. Professors at the University of Florida in Gainesville found that gamergates have more active insulin genes than regular worker ants and, as a result, have increased metabolic activity and ovary development. Experiments showed that he secret protecting the ants from insulin’s ageing effects appears to be a molecule called Imp-L2, which blocks the branch of the insulin pathway linked to ageing, while the branch involved in reproduction remains active. However, we still do not understand how Imp-L2 can effect one pathway and not the other.

These results aid our understanding of extreme social insect longevity massively, the researchers say, as well as displaying an anti-ageing evolutionary adaptation that hasn’t been seen in the wild before.

Page updated

Report abuse