Western University researchers have discovered the Colorado potato beetle has a unique ability that allows it to preserve energy during winter hibernation.
The little bug can break down and regrow its muscles on demand, according to the team of insect physiologists.
The discovery was a bit of a happy-accident. The scientists were trying to measure the beetle's metabolic rate of its mitochondria - membrane-bound cell organelles that supply energy for flight and metabolism - when they determined it had none.
“We know that lots of animals try to save energy and reduce their metabolic rate in the winter by turning down their mitochondria,” Western professor and study lead Brent Sinclair said. “So it seemed like a simple experiment to show that the low metabolic rates we measure in these overwintering beetles were associated with a change in the way the mitochondria function.”
Former graduate student Jackie Lebenzon was tasked with taking the measurement and at first believed the lack of mitochondria was due to an equipment failure in the lab.
"We thought maybe the instrument wasn’t working, or my sampling was damaging the mitochondria, but eventually, I used an electron microscope to look at the muscle cells and found that almost all of the mitochondria were gone. Completely gone," said Lebenzon.
But when researchers reexamined the same beetles at the end of winter they found all of the mitochondria were back.
"This ability to simply regrow an entire muscle’s worth of mitochondria is completely novel, and explains how beetles are able to save energy all winter, yet be ready to fly and mate immediately in the spring,” said Lebenzon.
More research is needed to determine whether all hibernating insects use this energy-saving strategy. However, the discovery does have immediate implications for understanding mitochondria regulation in insects, which could potentially be manipulated to help treat people suffering from some muscular diseases.
The study was published in the high-impact journal PNAS.