Enriquez Thomas, Renault David, Charrier Maryvonne, Colinet Hervé
ECOBIO - UMR 6553, Université de Rennes 1, CNRS, Rennes, France.
Institut Universitaire de France, Paris, France.
Front Physiol. 2018 Nov 1;9:1506. doi: 10.3389/fphys.2018.01506. eCollection 2018.
The invasive fruit fly pest, , is a chill susceptible species, yet it is capable of overwintering in rather cold climates, such as North America and North Europe, probably thanks to a high cold tolerance plasticity. Little is known about the mechanisms underlying cold tolerance acquisition in . In this study, we compared the effect of different forms of cold acclimation (at juvenile or at adult stage) on subsequent cold tolerance. Combining developmental and adult cold acclimation resulted in a particularly high expression of cold tolerance. As found in other species, we expected that cold-acclimated flies would accumulate cryoprotectants and would be able to maintain metabolic homeostasis following cold stress. We used quantitative target GC-MS profiling to explore metabolic changes in four different phenotypes: control, cold acclimated during development or at adult stage or during both phases. We also performed a time-series GC-MS analysis to monitor metabolic homeostasis status during stress and recovery. The different thermal treatments resulted in highly distinct metabolic phenotypes. Flies submitted to both developmental and adult acclimation were characterized by accumulation of cryoprotectants (carbohydrates and amino acids), although concentrations changes remained of low magnitude. After cold shock, non-acclimated chill-susceptible phenotype displayed a symptomatic loss of metabolic homeostasis, correlated with erratic changes in the amino acids pool. On the other hand, the most cold-tolerant phenotype was able to maintain metabolic homeostasis after cold stress. These results indicate that cold tolerance acquisition of depends on physiological strategies similar to other drosophilids: moderate changes in cryoprotective substances and metabolic robustness. In addition, the results add to the body of evidence supporting that mechanisms underlying the different forms of acclimation are distinct.
入侵性果蝇害虫[此处原文可能缺失果蝇具体名称]是一种对寒冷敏感的物种，但它能够在相当寒冷的气候中越冬，比如在北美和北欧，这可能得益于其较高的耐寒可塑性。关于[此处原文可能缺失果蝇具体名称]耐寒性获得的潜在机制知之甚少。在本研究中，我们比较了不同形式的冷驯化（幼虫期或成虫期）对后续耐寒性的影响。结合发育阶段和成虫期的冷驯化导致了特别高的耐寒性表达。正如在其他物种中发现的那样，我们预期冷驯化的果蝇会积累抗冻剂，并能够在冷应激后维持代谢稳态。我们使用定量目标气相色谱 - 质谱分析来探索四种不同表型的代谢变化：对照组、发育阶段冷驯化、成虫期冷驯化或两个阶段都冷驯化。我们还进行了时间序列气相色谱 - 质谱分析，以监测应激和恢复过程中的代谢稳态状态。不同的热处理导致了高度不同的代谢表型。经过发育阶段和成虫期驯化的果蝇的特征是积累了抗冻剂（碳水化合物和氨基酸），尽管浓度变化幅度仍然较小。冷休克后，未驯化的冷敏感表型表现出代谢稳态的症状性丧失，与氨基酸池的不稳定变化相关。另一方面，最耐寒的表型在冷应激后能够维持代谢稳态。这些结果表明，[此处原文可能缺失果蝇具体名称]的耐寒性获得依赖于与其他果蝇类似的生理策略：抗冻物质的适度变化和代谢稳健性。此外，这些结果增加了支持不同形式驯化背后机制不同的证据。
