TY - JOUR

T1 - Metabolomic profiling of rapid cold hardening and cold shock in Drosophila melanogaster

AU - Overgaard, Johannes

AU - Malmendal, Anders

AU - Sørensen, Jesper

AU - Bundy, Jacob G

AU - Loeschcke, Volker

AU - Nielsen, Niels Chr

AU - Holmstrup, Martin

PY - 2007/12/1

Y1 - 2007/12/1

N2 - A short exposure to a mild cold stress is sufficient to increase cold tolerance in many insects. This phenomenon, termed rapid cold hardening (RCH) expands the thermal interval that can be exploited by the insect. To investigate the possible role of altered metabolite levels during RCH, the present study used untargeted (1)H NMR metabolomic profiling to examine the metabolomic response in Drosophila melanogaster during the 72 h following RCH and cold shock treatment. These findings are discussed in relation to the costs and benefits of RCH that are measured in terms of survival and reproductive output. Cold shock caused a persistent disturbance of the metabolite profile that correlated well with a delayed onset of cold shock mortality. The disruption of metabolite homeostasis was smaller following RCH, where control levels were fully recovered after 72 h. RCH improved both survival and reproductive output after a subsequent cold shock but the RCH treatment alone was associated with costs in terms of reduced survival and reproductive output. The most pronounced changes following the RCH treatment were elevated levels of glucose and trehalose. Although, it is difficult to discern if a change in a specific metabolite is linked to physiological processes of adaptive, neutral or detrimental nature we observed that the onset and magnitude of the increased sugar levels correlated tightly with the improved chill tolerance following RCH. These findings suggest a putative role of cryoprotectants during RCH which are discussed in the light of the existing literature on the mechanistic background of RCH.

AB - A short exposure to a mild cold stress is sufficient to increase cold tolerance in many insects. This phenomenon, termed rapid cold hardening (RCH) expands the thermal interval that can be exploited by the insect. To investigate the possible role of altered metabolite levels during RCH, the present study used untargeted (1)H NMR metabolomic profiling to examine the metabolomic response in Drosophila melanogaster during the 72 h following RCH and cold shock treatment. These findings are discussed in relation to the costs and benefits of RCH that are measured in terms of survival and reproductive output. Cold shock caused a persistent disturbance of the metabolite profile that correlated well with a delayed onset of cold shock mortality. The disruption of metabolite homeostasis was smaller following RCH, where control levels were fully recovered after 72 h. RCH improved both survival and reproductive output after a subsequent cold shock but the RCH treatment alone was associated with costs in terms of reduced survival and reproductive output. The most pronounced changes following the RCH treatment were elevated levels of glucose and trehalose. Although, it is difficult to discern if a change in a specific metabolite is linked to physiological processes of adaptive, neutral or detrimental nature we observed that the onset and magnitude of the increased sugar levels correlated tightly with the improved chill tolerance following RCH. These findings suggest a putative role of cryoprotectants during RCH which are discussed in the light of the existing literature on the mechanistic background of RCH.

KW - Adaptation, Physiological

KW - Animals

KW - Cold Temperature

KW - Drosophila melanogaster

KW - Longevity

KW - Magnetic Resonance Spectroscopy

KW - Reproduction

KW - Time Factors

U2 - 10.1016/j.jinsphys.2007.06.012

DO - 10.1016/j.jinsphys.2007.06.012

M3 - Journal article

C2 - 17662301

VL - 53

SP - 1218

EP - 1232

JO - Journal of Insect Physiology

JF - Journal of Insect Physiology

SN - 0022-1910

IS - 12

ER -