The Secret of Longevity Lies in the Queen Honey Bee

In our search for longevity, the queen honey bee can give us many clues.

She is genetically the same with the workers in her hive, but while the workers live for a few months, she can live 10 times longer (up to 10 years) than her sterile sisters and reproducing throughout all her life.

A new research at the University of Illinois discovered three molecules responsible for this difference, all involved in reproduction, growth and/or longevity: vitellogenin (Vg, a yolk protein linked to reproduction but also found to prolong life in worker bees), the juvenile hormone (involved in growth and maturation) and an insulin-IGF-1 signaling pathway (IIS), linked to aging, fertility and other crucial biological processes in both invertebrates and vertebrates. "Many times the way organisms achieve longevity is via a tradeoff with reproduction," said main researcher Gene Robinson, entomology professor.

"In general, life forms that postpone reproduction until later in life live longer. But the queen bee is an egg-laying machine. She lays 2,000 eggs a day and yet lives 10 times longer than individuals that stem from the same genome and yet do not reproduce."

In the case of the fruit fly and the nematod worms, down-regulation of IIS was linked to higher longevity but lower fertility.

Vg is formed in fat body cells in honey bees, and manipulation of these cells in the head of the fruit fly resulted in an increased longevity.

This research found that Vg expression was high in the abdomen in the young queen and dropped with the age, but boosted in the head and thorax so that in the end old queens displayed more Vg than young ones. Worker bees had much lower levels of Vg expression than queens had, and Vg in worker heads was also low compared to its level in the queens. It is known that Vg decreases oxidative stress by eliminating free radicals that make the organism more prone to aging or disease.

Queens proved to be indeed more resistant to oxidative stress than the sterile workers were. "Whether this is the actual mechanism by which queens achieve both fertility and long life remains to be seen," Robinson said.

"This study suggests that vitellogenin plays a vital role in queen bee longevity, particularly since the honey bee lacks many antioxidants commonly found in other species. There are implications here (for other species) in the sense that here is an organism that is reproductively active and long-lived. And humans want to know how that works", Robinson said.