Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria.
Central Research Laboratories, Natural History Museum of Vienna, Vienna, Austria.
Sci Rep. 2023 Aug 23;13(1):13792. doi: 10.1038/s41598-023-40781-7.
Temperature fluctuations are challenging for ectotherms which are not able to regulate body temperature by physiological means and thus have to adjust their thermal environment via behavior. However, little is yet known about whether microbial symbionts influence thermal preference (T) in ectotherms by modulating their physiology. Several recent studies have demonstrated substantial effects of Wolbachia infections on host T in different Drosophila species. These data indicate that the direction and strength of thermal preference variation is strongly dependent on host and symbiont genotypes and highly variable among studies. By employing highly controlled experiments, we investigated the impact of several environmental factors including humidity, food quality, light exposure, and experimental setup that may influence T measurements in adult Drosophila melanogaster flies. Additionally, we assessed the effects of Wolbachia infection on T of Drosophila at different developmental stages, which has not been done before. We find only subtle effects of Wolbachia on host T which are strongly affected by experimental variation in adult, but not during juvenile life stages. Our in-depth analyses show that environmental variation has a substantial influence on T which demonstrates the necessity of careful experimental design and cautious interpretations of T measurements together with a thorough description of the methods and equipment used to conduct behavioral studies.
温度波动对变温动物来说是一个挑战，因为它们无法通过生理手段来调节体温，所以必须通过行为来调整它们的热环境。然而，目前还不清楚微生物共生体是否通过调节宿主的生理机能来影响变温动物的热偏好（T）。最近的几项研究表明，沃尔巴克氏体感染对不同果蝇物种的宿主 T 有显著影响。这些数据表明，热偏好变化的方向和强度强烈依赖于宿主和共生体的基因型，并且在研究之间高度可变。通过采用高度控制的实验，我们研究了包括湿度、食物质量、光照暴露和实验设置在内的几个环境因素对成年黑腹果蝇 T 测量的影响。此外，我们评估了沃尔巴克氏体感染对不同发育阶段果蝇 T 的影响，这在以前的研究中尚未进行过。我们发现沃尔巴克氏体对宿主 T 的影响很小，而且在成年阶段的实验变化中受到强烈影响，但在幼年阶段则不受影响。我们的深入分析表明，环境变化对 T 有很大的影响，这表明在进行行为研究时，需要仔细的实验设计和谨慎的 T 测量解释，并对用于进行行为研究的方法和设备进行详细描述。
