Arctic Fly Larvae Survive Liquid Nitrogen Cryopreservation

[TECH NEWS]

The larva of the arctic drosophilid fly, Chymomyza costata, is probably the most complex multicellular organism that can survive submergence in liquid nitrogen (-196 °C) in a fully hydrated state. A research team in the Czech Republic headed by Vladimír Koštál examined the associations between the physiological and biochemical parameters of differently acclimated larvae and their freeze tolerance. Entering diapause, a metabolically dormant state, is an essential and sufficient prerequisite for attaining high levels of survival in liquid nitrogen (23% survival to adult stage), although cold acclimation further substantially improves this capacity (62% survival). Profiling of 61 different metabolites identified proline as a prominent compound whose concentration greatly increased (from 20 to 147 mM) during diapause transition and subsequent cold acclimation. The study provides direct evidence for the essential role of proline in high freeze tolerance. Levels of proline in the larval tissues were increased by feeding larvae proline-augmented diets. The researchers found that this simple treatment dramatically improved their freeze tolerance.

 June 30, 2011, Proceedings of the National Academy of Sciences (US)