Low rank and primiparity increase fecal glucocorticoid metabolites across gestation in wild geladas
Low rank and primiparity increase fecal glucocorticoid metabolites across gestation in wild geladas
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DOI：
10.1016/j.ygcen.2020.113494
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发表时间：
2020-07-01
影响因子：
2.7
通讯作者：
Beehner, Jacinta C.
中科院分区：
文献类型：
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作者：
Carrera, Sofia C.;Sen, Sharmi;Beehner, Jacinta C.
在野生动物种群的研究中，综合行为生态学需要精确和非侵入性的激素调节措施。测量激素及其代谢物的生物敏感分析系统需要针对感兴趣的物种和样品介质(如尿液、粪便、唾液)进行验证。在可用于激素(代谢物)测量的不止一种检测方法的情况下，抗体选择对于确定跟踪个体内分泌活动变化最好的检测方法是有用的，即最生物敏感的检测方法。这在测量糖皮质激素(GC)如何在可预测的代谢挑战(如妊娠)期间对急性应激源的微妙、相加的影响做出反应时尤为重要。在这里，我们验证了一种群特异性酶免疫分析方法，该方法用于野生灵长类动物美洲狮(Theropithecus Gelada)，测量免疫活性11β-羟乙硫胆碱酮。这种组特异性检测产生的值与先前验证的双抗体皮质酮I-125放射免疫法的值相关。然而，与皮质酮试验相比，组特异性试验的结果显示对ACTH攻击的反应更强，并发现与皮质酮试验相比，Gelada免疫反应粪便糖皮质激素代谢产物(IGCM)的变化更大，表明在评估肾上腺皮质活动方面具有更高的生物学敏感性。然后，我们使用组特异性分析来：(1)确定妊娠期间iGCM水平的标准模式，以及(2)确定影响怀孕雌性GC产量的生态、社会和个人因素。使用一般的加法混合模型，我们发现较高的iGCM水平与低级别(与高级别相比)和第一次母亲(与经产母亲相比)相关。这项研究强调了在非侵入性采集的样本中进行激素研究的方法选择的重要性和组特异性方法的有效性。此外，在Geladas中，我们的结果确定了一些因素，这些因素增加了GC产量，而不是与妊娠相关的已经升高的GC浓度。在方兴未艾的母体应激领域，可以研究这些因素，以确定GC升高可能对后代发育产生的影响。
Integrative behavioral ecology requires accurate and non-invasive measures of hormone mediators for the study of wild animal populations. Biologically sensitive assay systems for the measurement of hormones and their metabolites need to be validated for the species and sample medium (e.g. urine, feces, saliva) of interest. Where more than one assay is available for hormone (metabolite) measurement, antibody selection is useful in identifying the assay that tracks changes in an individuals endocrine activity best, i.e., the most biologically sensitive assay. This is particularly important when measuring how glucocorticoids (GCs) respond to the subtle, additive effects of acute stressors during a predictable metabolic challenge, such as gestation. Here, we validate a group-specific enzyme immunoassay, measuring immunoreactive 11 beta-hydroxyetiocholanolone, for use in a wild primate, geladas (Theropithecus gelada). This group-specific assay produced values correlated with those from a previously validated double-antibody, corticosterone I-125 radioimmunoassay. However, the results with the group-specific assay showed a stronger response to an ACTH challenge and identified greater variation in gelada immunoreactive fecal glucocorticoid metabolites (iGCMs) compared with the corticosterone assay, indicating a higher biological sensitivity for assessing adrenocortical activity. We then used the group-specific assay to: (1) determine the normative pattern of iGCM levels across gelada gestation, and (2) identify the ecological, social, and individual factors that influence GC output for pregnant females. Using a general additive mixed model, we found that higher iGCM levels were associated with low rank (compared to high rank) and first time mothers (compared to multiparous mothers). This study highlights the importance of assay selection and the efficacy of group-specific assays for hormonal research in non-invasively collected samples. Additionally, in geladas, our results identify some of the factors that increase GC output over and above the already-elevated GC concentrations associated with gestation. In the burgeoning field of maternal stress, these factors can be examined to identify the effects that GC elevations may have on offspring development.