首页 | 本学科首页   官方微博 | 高级检索  
     


Heat tolerance in Drosophila subobscura along a latitudinal gradient: Contrasting patterns between plastic and genetic responses
Authors:Luis E. Castañeda  Enrico L. Rezende  Mauro Santos
Affiliation:1. Instituto de Ecología y Biodiversidad (IEB‐Chile), Santiago, Chile;2. Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile;3. Department of Life Sciences, University of Roehampton, London, United Kingdom;4. Departament de Genètica i de Microbiologia, Grup de Genòmica, Bioinformàtica i Biologia Evolutiva (GGBE), Universitat Autonòma de Barcelona, Bellaterra (Barcelona), Spain
Abstract:Susceptibility to global warming relies on how thermal tolerances respond to increasing temperatures through plasticity or evolution. Climatic adaptation can be assessed by examining the geographic variation in thermal‐related traits. We studied latitudinal patterns in heat tolerance in Drosophila subobscura reared at two temperatures. We used four static stressful temperatures to estimate the thermal death time (TDT) curves, and two ramping assays with fast and slow heating rates. Thermal death time curves allow estimation of the critical thermal maximum (CTmax), by extrapolating to the temperature that would knock down the flies almost “instantaneously,” and the thermal sensitivity to increasing stressful temperatures. We found a positive latitudinal cline for CTmax, but no clinal pattern for knockdown temperatures estimated from the ramping assays. Although high‐latitude populations were more tolerant to an acute heat stress, they were also more sensitive to prolonged exposure to less stressful temperatures, supporting a trade‐off between acute and chronic heat tolerances. Conversely, developmental plasticity did not affect CTmax but increased the tolerance to chronic heat exposition. The patterns observed from the TDT curves help to understand why the relationship between heat tolerance and latitude depends on the methodology used and, therefore, these curves provide a more complete and reliable measurement of heat tolerance.
Keywords:Clinal patterns  heat tolerance  plasticity  thermal death time curve  trade‐offs
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号