Cold stress tolerance in Drosophila: Analysis of chill coma recovery in D-melanogaster

Drosophila melanogaster adults, grown at 21 degrees C, were distributed in groups of 50 after a light anaesthesia. Culture vials with flies were later submitted to a cold treatment at 0 degrees C. All adults entered a chill coma; the recovery time was measured at ambient temperature. 2. Recovery time was strongly influenced by recovery temperature, with shorter values between 20-25 degrees C. 3. Recovery time increased almost linearly with duration of cold treatment. 4. Recovery time was consistently larger for males than for females. It was highly variable among groups and increased with flies' age. 5. Variability among flies of the same group was always very high, with CVs often over 25%. 6. Chill coma and its recovery seem to imply a modification of the nervous system, analogous in several aspects to what is observed with usual anaesthetics such as CO2. (C) 1998 Elsevier Science Ltd. All rights reserved.