Starkloff Naima C, Kirchman Jeremy J, Jones Andrew W, Winger Benjamin M, Huang Yen-Hua, Pulgarín-R Paulo C, Turner Wendy C
Department of Biological Sciences University at Albany State University of New York Albany NY USA.
New York State Museum Albany NY USA.
Ecol Evol. 2020 Jun 9;10(12):5402-5415. doi: 10.1002/ece3.6283. eCollection 2020 Jun.
The latitudinal diversity gradient (LDG) is an established macroecological pattern, but is poorly studied in microbial organisms, particularly parasites. In this study, we tested whether latitude, elevation, and host species predicted patterns of prevalence, alpha diversity, and community turnover of hemosporidian parasites. We expected parasite diversity to decrease with latitude, alongside the diversity of their hosts and vectors. Similarly, we expected infection prevalence to decrease with latitude as vector abundances decrease. Lastly, we expected parasite community turnover to increase with latitudinal distance and to be higher between rather than within host species. We tested these hypotheses by screening blood and tissue samples of three closely related avian species in a clade of North American songbirds (Turdidae: , = 466) across 17.5° of latitude. We used a nested PCR approach to identify parasites in hemosporidian genera that are transmitted by different dipteran vectors. Then, we implemented linear-mixed effects and generalized dissimilarity models to evaluate the effects of latitude, elevation, and host species on parasite metrics. We found high diversity of hemosporidian parasites in thrushes ( = 44 lineages) but no evidence of latitudinal gradients in alpha diversity or prevalence. Parasites in the genus were most prevalent and lineage rich in this study system; however, there was limited turnover with latitude and host species. Contrastingly, parasites were less prevalent and diverse than parasites, yet communities turned over at a higher rate with latitude and host species. communities were skewed by the dominance of one or two highly prevalent lineages with broad latitudinal distributions. The few studies that evaluate the hemosporidian LDG do not find consistent patterns of prevalence and diversity, which makes it challenging to predict how they will respond to global climate change.
纬度多样性梯度（LDG）是一种已确立的宏观生态模式，但在微生物有机体，尤其是寄生虫中研究较少。在本研究中，我们测试了纬度、海拔和宿主物种是否能预测血孢子虫寄生虫的流行模式、α多样性和群落周转率。我们预计寄生虫多样性会随着纬度降低，与其宿主和媒介的多样性一同降低。同样，我们预计随着媒介丰度降低，感染流行率会随纬度降低。最后，我们预计寄生虫群落周转率会随着纬度距离增加，且在宿主物种之间而非宿主物种内部更高。我们通过筛选北美鸣禽（鸫科： ， = 466）一个进化枝中三种亲缘关系密切的鸟类物种的血液和组织样本，跨越17.5°纬度来检验这些假设。我们使用巢式PCR方法来鉴定由不同双翅目媒介传播的血孢子虫属中的寄生虫。然后，我们实施线性混合效应和广义相异模型来评估纬度、海拔和宿主物种对寄生虫指标的影响。我们在画眉中发现了高多样性的血孢子虫寄生虫（ = 44个谱系），但没有证据表明α多样性或流行率存在纬度梯度。在本研究系统中， 属的寄生虫最为普遍且谱系丰富；然而，随着纬度和宿主物种的变化，其周转率有限。相比之下， 寄生虫比 寄生虫的流行率和多样性更低，但群落随纬度和宿主物种的周转率更高。 群落因一两个具有广泛纬度分布的高度流行谱系的主导而出现偏差。少数评估血孢子虫LDG的研究没有发现一致的流行率和多样性模式，这使得预测它们将如何应对全球气候变化具有挑战性。
