University Center for Research and Development, Chandigarh University, Gharuan, Mohali, 140413, India.
Genomics and Bioinformatics Cluster, Department of Biology, University of Central Florida, 4110 Libra Drive, Orlando, FL, 32816, USA.
Genetica. 2020 Aug;148(3-4):173-182. doi: 10.1007/s10709-020-00100-8. Epub 2020 Aug 13.
Beneficial acclimation hypothesis (BAH) is the phenotypic plasticity in response to changing environments which enables organisms to enhance their fitness. In recent years, however, BAH has received vigorous criticism and is still debatable. In this study, we tested thermal hardiness phenotypes (melanization, chill coma recovery, heat knockdown and percentage survival) on adult and pre-adult stages of Drosophila nepalensis, reared in different thermal environments (14, 17, 21 and 25 °C) to check whether increasing natural surrounding temperature and acclimation limit towards environmental change is detrimental or beneficial. Results showed that rearing D. nepalensis at higher temperatures (21 and 25 °C) reduces its melanization and cold hardiness but improves heat knockdown times. When temperature was raised to 26.2 °C (0.6 °C above the upper thermal maxima), to determine the short-term acclimation effects, survival and fitness of adults diminished approximately 1.5 to 2 folds. These results suggest that D. nepalensis has long-term developmental acclimation to both heat and cold which would be extremely beneficial as temperatures and climates alter in the region due to global warming. However, a lack of short-term heat acclimation suggests that rapid shifts in thermal extreme could be detrimental to D. nepalensis.
有益驯化假说（BAH）是生物体对环境变化的表型可塑性，使它们能够提高适应性。然而，近年来，BAH 受到了强烈的批评，仍然存在争议。在这项研究中，我们测试了成年和未成年的尼泊尔果蝇在不同热环境（14、17、21 和 25°C）下的热硬度表型（黑化、冷昏迷恢复、热击倒和存活率），以检查自然环境温度升高和驯化极限是否对环境变化有害或有益。结果表明，在较高温度（21 和 25°C）下饲养尼泊尔果蝇会降低其黑化和耐寒性，但会提高热击倒时间。当温度升高到 26.2°C（比最高温度高 0.6°C）时，为了确定短期驯化的影响，成虫的存活率和适应性降低了约 1.5 到 2 倍。这些结果表明，尼泊尔果蝇对热和冷都有长期的发育驯化，这在全球变暖导致该地区温度和气候发生变化时将是非常有益的。然而，缺乏短期耐热驯化表明，热极端的快速变化可能对尼泊尔果蝇有害。
