Stahlschmidt Z R, Adamo S A
Dalhousie University, Halifax, Nova Scotia, Canada.
Naturwissenschaften. 2013 Jul;100(7):691-6. doi: 10.1007/s00114-013-1057-y. Epub 2013 May 26.
Fever can reduce mortality in infected animals. Yet, despite its fitness-enhancing qualities, fever often varies among animals. We used several approaches to examine this variation in insects. Texas field crickets (Gryllus texensis) exhibited a modest fever (1 °C increase in preferred body temperature, T pref) after injection of prostaglandin, which putatively mediates fever in both vertebrates and invertebrates, but they did not exhibit fever during chronic exposure to heat-killed bacteria. Further, chronic food limitation and mating status did not affect T pref or the expression of behavioural fever, suggesting limited context dependency of fever in G. texensis. Our meta-analysis of behavioural fever studies indicated that behavioural fever occurs in many insects, but it is not ubiquitous. Thus, both empirical and meta-analytical results suggest that the fever response in insects 'is widespread, although certainly not inevitable' (Moore 2002). We highlight the need for future work focusing on standardizing an experimental protocol to measure behavioural fever, understanding the specific mechanism(s) underlying fever in insects, and examining whether ecological or physiological costs often outweigh the benefits of fever and can explain the sporadic nature of fever in insects.
发热可降低受感染动物的死亡率。然而，尽管发热具有增强适应性的特性，但动物之间的发热情况往往存在差异。我们采用了几种方法来研究昆虫的这种差异。德克萨斯田野蟋蟀（Gryllus texensis）在注射前列腺素后会出现适度发热（偏好体温T pref升高1°C），前列腺素被认为在脊椎动物和无脊椎动物中均可介导发热，但在长期接触热灭活细菌期间它们并未表现出发热。此外，长期食物限制和交配状态并不影响T pref或行为性发热的表现，这表明德克萨斯田野蟋蟀的发热对环境的依赖性有限。我们对行为性发热研究的荟萃分析表明，行为性发热在许多昆虫中都会出现，但并非普遍存在。因此，实证研究和荟萃分析结果均表明，昆虫的发热反应虽然肯定不是必然的，但却是普遍存在的（摩尔，2002年）。我们强调，未来的研究需要聚焦于标准化测量行为性发热的实验方案，了解昆虫发热背后的具体机制，以及研究生态或生理成本是否常常超过发热的益处，并能否解释昆虫发热的偶发性。
