Cold tolerance and metabolic rate increased by cold acclimation in <i>Drosophila albomicans</i> from natural populations

Abstract

Cold acclimation is one of the important factors in temperature adaptation for insects needing to make rapid adjustment to the seasonal temperature changes in their living environment. In a fruit fly species, Drosophila albomicans, which has a tropical origin and currently has a wide geographic distribution extended into Asian temperate regions, cold tolerance in terms of survival time at 1°C of adult flies reared at 25°C was substantially improved by a cold acclimation at 20°C for several days. Examining 29 isofemale lines from widely distributed natural populations, we observed a substantial variation in their acclimation response. However, the acclimation response was not necessarily stronger in the strains from the recently colonized temperate regions. A significantly stronger acclimation response was detected in male flies of the temperate strains when compared to those of the tropical strains. D. albomicans also showed stronger cold tolerance compared to its closely related species belonging to the D. nasuta subgroup. Among these strains, we detected a strong positive correlation between the cold tolerance change and the metabolic rate change upon the cold acclimation, suggesting their strong physiological association regulated by common genetic factors, which may have been the target of natural selection for the temperature adaptation. The response to deacclimation and reacclimation suggested that a systematic change in gene expressions is the main molecular mechanism for the cold acclimation to have effects on the cold tolerance and metabolic rate changes.

Cold Acclimation Favors Metabolic Stability in Drosophila suzukii

“…Indeed, metabolic cold adaptation or temperature compensation theories presume that at a same temperature, cold hardy insects showed similar or even higher metabolic rate than cold sensitive individuals ( Hazel and Prosser, 1974 ; Chown and Gaston, 1999 ). Even if these theories are not always supported, several studies showed that cold acclimated insects had higher metabolic rate than warm acclimated ones ( Terblanche et al, 2005 ; Isobe et al, 2013 ) and this may explain, at least in part, the changes in levels of TCA intermediates.…”

High frequency of horizontal transfer in Jockey families (LINE order) of drosophilids

“…Additionally, in Jockey-F67, the HTT occurred between D. obscura and S. lebanonensis , which are widespread in the Palaeartic region. Moreover, although not validated by the VHICA and thus not considered an HTT event here, two extra incongruities involved widespread species, namely, D. suzukii [52] and D. albomicans [53], respectively in Jockey-F6 and Jockey-F52. The reason for the relationship between a widespread distribution and HTT needs to be investigated; however, what seems clear is that the ability of these species to disperse increases the chance of phylogenetic jumps of viruses, potential candidates to move TEs from one genome into another [54].…”

Characterization and Structural Determination of Cold-Adapted Monodehydroascorbate Reductase, MDHAR, from the Antarctic Hairgrass Deschampsia Antarctica

“…Low temperatures, particularly freezing temperatures, can dramatically impact plants at cellular to ecosystem scales [3]. To cope with cold stress, plant species have evolved adaptations in physiological and molecular functions to boost their cold tolerance by increasing their metabolic rates upon cold acclimation [4,5]. For example, plants in the Antarctic region have long life cycles, an extended primordium development of leaves and flowers, well-developed root systems, and efficient photosynthetic and respiratory systems at 10 • C or lower [1,6,7].…”