Department of Biology, Laurentian University, 935 Ramsey Lake Road, Sudbury, ON P3E 2C6, Canada. Electronic address: https://www.0000-0003-0010-3475.
Ontario Ministry of Natural Resources and Forestry, Wildlife Research and Monitoring Section, 2140 East Bank Drive, DNA Building, Peterborough, ON K9L 0G2, Canada; Trent University, 1600 East Bank Drive, Peterborough, ON K9L 0G2, Canada.
Gen Comp Endocrinol. 2021 Jan 1;300:113640. doi: 10.1016/j.ygcen.2020.113640. Epub 2020 Oct 2.
A common response to parasite infestations is increased production of glucocorticoid hormones that regulate immune function. We examined relationships between ectoparasite infestations and fecal corticosterone metabolites (FCM) in deer mice (Peromyscus maniculatus). Furthermore, we experimentally removed fleas to determine if reductions in ectoparasites affected FCM production. Individuals were assigned to control (no flea removal) or treatment (anti-flea application, physical combing) groups and individuals were recaptured to assess changes in FCM concentrations. There was a significant and negative effect of number of anti-flea treatment applications on FCM concentrations of deer mice. However, models including host biology traits and environmental predictors had a better model fit compared to models containing ectoparasite predictors. In particular, there was a significant relationship of deer mouse FCM with date and host age, where glucocorticoid production decreased towards the end of the breeding season and increased with age. Overall, adverse events associated with reproduction and age class, rather than ectoparasites, may be more important to variation in glucocorticoids of deer mice.
对寄生虫感染的常见反应是糖皮质激素激素的产生增加，这些激素调节免疫功能。我们研究了外寄生虫感染与鹿鼠（Peromyscus maniculatus）粪便皮质酮代谢物（FCM）之间的关系。此外，我们通过实验去除跳蚤，以确定减少外寄生虫是否会影响 FCM 的产生。个体被分配到对照组（不除蚤）或治疗组（除蚤处理、物理梳理），并对个体进行重捕，以评估 FCM 浓度的变化。鹿鼠的 FCM 浓度与除蚤处理次数呈显著负相关。然而，包含宿主生物学特征和环境预测因子的模型比包含外寄生虫预测因子的模型具有更好的拟合度。特别是，鹿鼠 FCM 与日期和宿主年龄呈显著关系，皮质酮的产生在繁殖季节末期减少，并随年龄增加而增加。总的来说，与繁殖和年龄有关的不良事件，而不是外寄生虫，可能对外寄生虫更重要鹿鼠的糖皮质激素变化。
