Abstract:
Variation in food resources can result in dramatic fluctuations in the body condition of animals dependent on those resources. Decreases in body mass can disrupt patterns of energy allocation and impose stress, thereby altering immune function. In this study, we investigated links between changes in body mass of captive cane toads (Rhinella marina), their circulating white blood cell populations, and their performance in immune assays. Captive toads that lost weight over a three-month period had increased levels of monocytes and heterophils and reduced levels of eosinophils. Basophil and lymphocyte levels were unrelated to changes in mass. Because individuals that lost mass had higher heterophil levels but stable lymphocyte levels, the ratio of these cell types was also higher, partially consistent with a stress response. Phagocytic ability of whole blood was higher in toads that lost mass, owing to increased circulating levels of phagocytic cells. Other measures of immune performance were unrelated to mass change. These results highlight the challenges faced by invasive species as they expand their range into novel environments which may impose substantial seasonal changes in food availability that were not present in the native range. Individuals facing energy restrictions may shift their immune function towards more economical and general avenues of combating pathogens. This article is part of the theme issue \'Amphibian immunity: stress, disease and ecoimmunology\'.
摘要:
食物资源的变化会导致依赖于这些资源的动物的身体状况的剧烈波动。身体质量的减少会破坏能量分配的模式并施加压力,从而改变免疫功能。在这项研究中,我们调查了圈养甘蔗蟾蜍(莱茵内拉码头)体重变化之间的联系,他们循环的白细胞群,以及它们在免疫测定中的表现。在三个月内体重减轻的圈养蟾蜍的单核细胞和异粒细胞水平升高,嗜酸性粒细胞水平降低。嗜碱性粒细胞和淋巴细胞水平与质量变化无关。因为失去质量的个体有更高的异性恋水平,但淋巴细胞水平稳定,这些细胞类型的比例也更高,部分与应激反应一致。失去质量的蟾蜍全血的吞噬能力更高,由于吞噬细胞的循环水平增加。免疫性能的其他指标与质量变化无关。这些结果突出了入侵物种面临的挑战,因为它们将其范围扩展到新的环境中,这可能会对本地范围内不存在的食物供应造成实质性的季节性变化。面临能量限制的个体可能会将其免疫功能转向更经济和通用的对抗病原体的途径。这篇文章是主题问题的一部分\'两栖动物的免疫力:压力,疾病和生态免疫学。