Insulin-resistant protein linked to longevity and reproduction in ants

Insulin-resistant protein linked to longevity and reproduction in ants

Harpegnathos saltator worker ants.Image credit: Huayan/NYU

An insulin-suppressing protein may be the source of youth in ants and provide clues to aging in other species, according to a study led by researchers at New York University.

published in scienceStudies have shown that queen ants exhibit a higher reproductive metabolism without undergoing senescence by producing an anti-insulin protein that blocks only part of the insulin pathway that causes senescence.

In many animals, having many offspring is associated with a shorter lifespan. This trade-off between an animal’s fertility and longevity is thought to be the result of how nutritional and metabolic resources are allocated.

Insulin — a hormone that helps convert food into energy — plays an important role in both metabolism and aging. Egg production is energy-intensive and requires additional food, which raises insulin levels, but the increased activity of the insulin pathway required for reproduction results in shorter lifespans in most animals. In contrast, dietary restriction extends lifespan by lowering insulin levels; in fact, other researchers are exploring whether fasting can prolong lifespan.

In Harpegnathos saltator ants, worker ants duel with their tentacles to establish a new leadership position after the death of their queen. The winner (or pseudo-queen) gains queen-like behavior, including spawning, and their life expectancy increases from seven months to four years.Credit: Giacomo Mancini/NYU

Ants are a notable exception to the trade-off between reproduction and longevity, because their queens — responsible for the reproduction of entire colonies — live much longer than workers while sharing the same genome. In species like the black garden ant, a single queen can lay a million eggs and live for 30 years, while her sterile worker sisters live only a year. Among the Harpegnathos saltator ants, a jumping ant native to India that was the focus of this study, queens typically live for five years, while workers live only seven months.

When Queen Harpegnathos dies in a colony, a strange thing happens: female worker ants fight each other with their tentacles to become the next queen. The duel winner changes “caste” in the ant society and becomes a pseudo-queen, also known as the player gate, while still remaining in the (lesser) worker body. Pseudo-queens acquire queen-like behavior, including spawning, and their life expectancy increases dramatically from seven months to four years. But if they are replaced by another queen, they revert to worker status, stop laying eggs, and their lifespan is shortened back to seven months.

Insulin-resistant protein linked to longevity and reproduction in ants

In situ hybridization of ant brain tissue shows increased insulin mRNA in the brains of pseudo-queen (right) and worker (left) ants.Credit: Giacomo Mancini/NYU

“By undergoing a reversible ‘caste switch’ from worker to pseudo-queen, resulting in a dramatic increase in their lifespan and reproductive capacity, Harpegnathos ants offer a unique opportunity to study how aging and reproduction are disconnected,” said the study’s co-senior investigators. . By Claude Desplan, NYU Silver Professor of Biology and Neuroscience.

Using bulk RNA sequencing, the researchers studied tissue samples from worker ants and pseudoqueens, focusing on the parts of the ant involved in metabolism and reproduction, including the brain, fat body (the insect’s liver), and ovary. They found that ants that switched from worker ants to pseudoqueens produced more insulin in the brain to lay eggs. This increased insulin leads to activation of one of the two main branches of the insulin signaling pathway, MAPK, which controls metabolism and egg formation.

Increased insulin in pseudoqueens induces ovarian development, which then begins to produce an insulin-suppressing protein called Imp-L2. Imp-L2 blocks signaling in AKT, another major branch of the insulin signaling pathway, which controls aging, and its increased activity leads to shorter lifespan.

Insulin-resistant protein linked to longevity and reproduction in ants

Harpegnathos saltator queens (pictured here, with wings) typically live five years, while workers only live seven months.Image credit: Huayan/NYU

“Two major branches of the insulin signaling pathway appear to be differentially regulating fertility and longevity, with an increase in one signal contributing to the reproduction of false queens, while a decrease in the other is consistent with its increased longevity,” said co-senior of the study. said author Danny Reinberg, Terry and Mel Karmazin Professor of Biochemistry and Molecular Pharmacology at NYU Grossman School of Medicine and Howard Hughes Medical Institute Investigator.

“This interaction, which has evolved in ants and other insects, may have resulted in abnormal longevity of ants and many offspring breeding ants,” said study co-first author Hua Yan, a former postdoctoral researcher at NYU Grossman School of Medicine. He now is an assistant professor of biology at the University of Florida.

“Our work also illustrates the importance of using appropriate model systems to ask questions about fundamental biology. For example, most manipulations of lifespan in animals such as mice or flies typically increase their lifespan by 10 to 20 percent. Ants Demonstrated an astonishing 500 percent increase in lifespan, which makes studying them even more powerful,” Desplan added.

Additional study authors include Comzit Opachaloemphan, Francisco Carmona-Aldana, Giacomo Mancini, Jakub Mlejnek, Nicolas Desccostes, Bogdan Sieriebriennikov, Alexandra Leibholz, Long Ding and Maria Traficante of New York University, and Xiaofan Zhou of South China Agricultural University.

Behavioral and molecular cues quickly determine who wins in duel for queen ant

More information:
Hua Yan et al., Insulin signaling in the long-lived reproductive caste of ants, science (2022). DOI: 10.1126/science.abm8767.

Courtesy of New York University

Citation: Anti-insulin protein linked to longevity and reproduction in ants (September 1, 2022) Retrieved on September 2, 2022 from -reproduction.html retrieve

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