Natures wonders: long-lived ant queens (Introduction)

by David Turell , Wednesday, January 11, 2023, 00:06 (471 days ago) @ David Turell

How they do it:

https://www.quantamagazine.org/ants-live-10-times-longer-by-altering-their-insulin-resp...

"In some ant species, queens live more than 30 years while laying the thousands upon thousands of eggs that become all the workers in the nest. In contrast, worker ants, which are females that don’t reproduce, live only months. Yet if circumstances demand it, the workers of some species can step up to become pseudo-queens for the good of the nest — and to reap a significant extension in their life span.

"What governs this gigantic range in ant life span is poorly understood, but two recent studies have revealed important details about what makes the life spans of ants so flexible. In Science, researchers at New York University showed that some ant queens produce a protein that suppresses the aging effect of insulin so that they can consume all the additional food needed for their egg-laying without shortening their lives. And in a preprint recently posted on the biorxiv.org server, researchers in Germany described a parasite that greatly lengthens the lives of its ant hosts by secreting a rich cocktail of antioxidants and other compounds. Both studies add to the evidence that the observed life spans of organisms have little to do with limitations imposed by their genes.

***

"...four years ago, when Vikram Chandra was a graduate student at Rockefeller University studying the differences between ant queens and workers, insulin was very much on his mind. He led a team that looked at gene expression in seven ant species and concluded that more insulin signaling occurred in the brains of the queens than in the workers. When they injected worker ants with insulin, it activated their dormant ovaries and triggered egg development. According to Kronauer, who was Chandra’s adviser, these findings showed that insulin signaling caused the ants to become reproductive.

***

"...from previous studies of insulin and aging, the NYU researchers had expected that greater insulin signaling would be linked to a shorter life span, not a longer one.

"The researchers found the answer hiding in the details of insulin signaling. When insulin binds to its receptor on a cell surface, it sets off cascades of reactions inside the cell, including two distinct chemical pathways. One pathway activates an enzyme called MAP kinase and is critical for metabolism and ovary development. The other pathway suppresses a transcription factor that seems to promote a longer life span. To the researchers’ surprise, when they looked at the ovary and the fat body (which is roughly equivalent to the mammalian liver) in gamergates, they found that the MAP kinase pathway was active but the other one was not.

"Further work showed that the ovaries of the gamergates strongly expressed a protein, Imp-L2, that ignored the MAP kinase pathway but interfered with the second pathway in the fat body. “This protein appears to have the function of protecting one pathway that allows metabolism, but inhibiting the pathway that leads to aging,” Desplan said."

Comment: this is an example of how a series of molecules deliver messages to active processes, to speed up or slow down. All of this happens automatically and cannot be evolved stepwise.