An international team of scientists led by Osaka Metropolitan University revealed one of the mysteries of the life cycle of the Antarctic midge, Belgica antarctica, which offers clues to humans about cryopreservation.
An international team of scientists led by Osaka Metropolitan University revealed how Antarctica sole known native insect–the Antarctic midge, or Belgica antarctica–survives the extreme cold.
Belgica antarctica's lives in winters where low temperatures range from -2 to -10 °C in a dormant state, as detailed by Nature. The small insect survives the freezing temperatures with unique latency strategies, including both quiescence and diapause.
"We developed a method for breeding Antarctic midges in the laboratory, which helped us understand their adaptation to extreme conditions," said Mizuki Yoshida from Osaka Metropolitan University.
The Antarctic midge is the only known insect native to the Antarctic continent and is endemic to the Antarctic Peninsula, surviving extreme climates that have historically puzzled scientists. Despite its small size, Belgica antarctica is one of the most resilient insects, adapting even to extreme cold.
The researchers discovered that the larvae of Belgica antarctica enter a state of inactivity, known as quiescence, that allows them to resume their development quickly whenever temperatures increase suddenly, enabling swift transitions between active and inactive lifestyles. In the first winter, the larvae reach the second developmental stage and enter quiescence in response to cold and lack of food, allowing them to quickly reactivate during temporary warming.
Before the second winter, as the insects are ready to pupate, the larvae reach the fourth and final stage but do not transform into pupae; instead, they enter obligatory diapause, a period of dormancy induced naturally at a fixed point in an organism's life cycle. "Unlike quiescence, obligatory diapause is a genetically preprogrammed pause in development: it occurs independently of environmental conditions," according to Professor Shin Goto.
This unique strategy allows all individuals to synchronously pupate and transform into adult midges by the beginning of summer, enhancing the likelihood of successful mating. Synchronization of adult emergence increases the chance of finding a mate during the limited time adults have to reproduce and is crucial for the survival of Belgica antarctica, according to SAPO.
This combination of quiescence and obligatory diapause has not been observed in other organisms, making the Antarctic midge's survival strategy unique. "Although seasonal adaptation strategies involving spending winter multiple times using both inactivity and forced diapause have not been described in other organisms, we believe that insects inhabiting hostile environments like the Arctic and high altitudes may be employing similar strategies," stated Professor Goto.
The article was written with the assistance of a news analysis system.