Departamento de Ciências Biológicas, Universidade Federal de São Paulo (UNIFESP), Diadema, SP, Brazil.
Department of Life Sciences, Natural History Museum, Cromwell Road, LondonSW7 5BD, UK.
Parasitology. 2021 Apr;148(5):511-518. doi: 10.1017/S0031182020002322. Epub 2020 Dec 10.
This study undertook the first investigation of malacosporean infections in Neotropical fish. We used polymerase chain reaction detection with a primer set generally targeting known malacosporeans to assay for infection in the kidney of 146 fish in 21 species belonging to 12 families collected from two areas in the Amazon Basin. Infections were found in 13 fish variously belonging to seven species in six families and included the first identification of a malacosporean infection in cartilaginous fish (a freshwater stingray). Based on ssrDNA, all infections represented a single Buddenbrockia species (Buddenbrockia sp. E) that demonstrates an exceptionally broad range of fish species infected, and countered our expectations of high Neotropical malacosporean diversity. Infections were characterized at varying and often high prevalences in fish species but sample sizes were small. Ascertaining whether highly divergent malacosporeans have not been detected by current primers, and more comprehensive sampling may reveal whether malacosporeans are truly as species poor in the Amazon Basin as present data suggest. Our results prompt speculations about evolutionary scenarios including introduction via marine incursions and patterns of host use over time.
本研究首次调查了新热带鱼类中的粘孢子虫感染。我们使用聚合酶链反应检测，使用一组通常针对已知粘孢子虫的引物，对来自亚马逊盆地两个地区的 21 个科 146 种鱼类的肾脏进行了感染检测。在 13 种不同鱼类中发现了感染，这些鱼类分属于 6 个科的 7 个种，包括首次在软骨鱼类（淡水黄貂鱼）中发现粘孢子虫感染。基于 ssrDNA，所有感染都代表了一种单一的 Buddenbrockia 种（Buddenbrockia sp. E），这种种显示出感染鱼类种类异常广泛，与我们对新热带粘孢子虫多样性高的预期相悖。在鱼类中，感染的流行率各不相同，而且往往很高，但样本量很小。目前的引物是否未能检测到高度分化的粘孢子虫，以及更全面的采样是否能揭示粘孢子虫在亚马逊盆地是否真的像现有数据所表明的那样物种稀少，还有待确定。我们的研究结果引发了对进化情景的猜测，包括通过海洋入侵和宿主利用模式的推测。
