Slow and stepped re-warming after acute low temperature exposure do not improve survival of Drosophila melanogaster larvae

摘要

We tested that hypothesis that slow re-warming rates would improve the ability of Drosophila melanogaster Meigen larvae to survive acute low temperature exposure. Four larval stages (1^st, 2^nd, 3^rd instars and wandering stage 3^rd instars) of four wild-type strains were exposed to −7 °C for periods of time expected to result in 90 % mortality. Larvae were then either directly transferred to their rearing temperature (21 °C), or returned to this temperature in a stepwise fashion (pausing at 0 and 15 °C) or by slow warming at 1 or 0.1 °C/min. We observed a reduced rapid cold-hardening effect and no general increase in survival of acute chilling in larvae re-warmed in a stepwise or slow fashion, and hypothesise that slow re-warming may result in accumulation of further chill injuries.