Reproduction has different costs for immunity and parasitism in a wild mammal
Reproduction has different costs for immunity and parasitism in a wild mammal
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DOI：
10.1111/1365-2435.13475
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发表时间：
2019-11-15
影响因子：
5.2
通讯作者：
Pemberton, Josephine M.
中科院分区：
文献类型：
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作者：
Albery, Gregory F.;Watt, Kathryn A.;Pemberton, Josephine M.
生活史理论预测，生殖分配会从免疫中抽走资源，导致寄生率增加。然而，关于生殖权衡的研究很少考察生殖、免疫和寄生的多种衡量标准。因此，目前尚不清楚生殖特征的免疫成本是否与它们的资源成本相关，以及寄生率的增加是否来自较弱的免疫力。我们研究了野生雌性马鹿(Cervus Elaffus)的这些关系，包括不同的生殖分配以及粘膜抗体水平和蠕虫寄生的纵向数据。非侵入性采集粪便标本，计数线虫、肝片吸虫和马鹿组织线虫的繁殖体。我们还对总免疫球蛋白A和抗强直肠粘膜免疫球蛋白A进行了量化，以测量一般免疫分配和特异性免疫分配。与我们的预测相反，我们发现怀孕与总IgA下降有关，但寄生率没有增加。同时，大量的哺乳资源需求没有进一步的免疫成本，但与较高的强线虫和E.Cervi数量有关。尽管抗体和强力球计数之间呈负相关，这意味着IgA是保护性免疫的指标，但这些对比成本仍然出现。我们的发现表明，除了经典的资源分配权衡外，其他过程也参与了野生哺乳动物繁殖、免疫和寄生之间的关系。具体地说，生殖免疫的权衡可能是荷尔蒙调节或母体抗体转移造成的，寄生率因资源获取限制而增加暴露而增加。我们主张在调查生殖成本时，仔细考虑独立于资源的机制联系，并衡量免疫和寄生。在本文的支持信息中可以找到免费的简明语言摘要。
Life history theory predicts that reproductive allocation draws resources away from immunity, resulting in increased parasitism. However, studies of reproductive trade-offs rarely examine multiple measures of reproduction, immunity and parasitism. It is therefore unclear whether the immune costs of reproductive traits correlate with their resource costs, and whether increased parasitism emerges from weaker immunity. We examined these relationships in wild female red deer (Cervus elaphus) with variable reproductive allocation and longitudinal data on mucosal antibody levels and helminth parasitism. We noninvasively collected faecal samples, counting propagules of strongyle nematodes (order: Strongylida), the common liver fluke Fasciola hepatica and the red deer tissue nematode Elaphostrongylus cervi. We also quantified both total and anti-strongyle mucosal IgA to measure general and specific immune allocation. Contrary to our predictions, we found that gestation was associated with decreased total IgA but with no increase in parasitism. Meanwhile, the considerable resource demand of lactation had no further immune cost but was associated with higher counts of strongyle nematodes and E. cervi. These contrasting costs arose despite a negative correlation between antibodies and strongyle count, which implied that IgA was indicative of protective immunity. Our findings suggest that processes other than classical resource allocation trade-offs are involved in mediating observed relationships between reproduction, immunity and parasitism in wild mammals. In particular, reproduction-immunity trade-offs may result from hormonal regulation or maternal antibody transfer, with parasitism increasing as a result of increased exposure arising from resource acquisition constraints. We advocate careful consideration of resource-independent mechanistic links and measurement of both immunity and parasitism when investigating reproductive costs. A free Plain Language Summary can be found within the Supporting Information of this article.