Park Eunji, Leander Brian
Department of Botany, University of British Columbia, Vancouver, Canada.
Department of Zoology, University of British Columbia, Vancouver, Canada.
Parasitology. 2024 Apr;151(4):400-411. doi: 10.1017/S0031182024000209. Epub 2024 Mar 11.
Individual organisms can host multiple species of parasites (or symbionts), and one species of parasite can infect different host species, creating complex interactions among multiple hosts and parasites. When multiple parasite species coexist in a host, they may compete or use strategies, such as spatial niche partitioning, to reduce competition. Here, we present a host–symbiont system with two species of (Apicomplexa, Gregarinida) and one species of astome ciliate co-infecting two different species of slime feather duster worms (Annelida, Sabellidae, ) living in neighbouring habitats. We examined the morphology of the endosymbionts with light and scanning electron microscopy (SEM) and inferred their phylogenetic interrelationships using small subunit (SSU) rDNA sequences. In the host ‘ sp. Quadra’, we found two distinct species of ; . cf. exclusively inhabited the foregut, and . n. sp. inhabited the mid to hindgut, reflecting spatial niche partitioning. n. sp. was also present in the host . , which harboured the astome ciliate n. gen. et sp. cf. and . n. gen. et sp. were absent in the other host species, indicating host specificity. This system offers an intriguing opportunity to explore diverse aspects of host–endosymbiont interactions and competition among endosymbionts.
单个生物体可以寄生多种寄生虫（或共生体），而一种寄生虫可以感染不同的宿主物种，从而在多个宿主和寄生虫之间形成复杂的相互作用。当多种寄生虫物种在一个宿主中共存时，它们可能会竞争或采用诸如空间生态位划分等策略来减少竞争。在这里，我们展示了一个宿主 - 共生体系统，其中两种（顶复门，簇虫纲）和一种无口纤毛虫共同感染生活在相邻栖息地的两种不同的黏液羽鳃虫（环节动物门，缨鳃虫科， ）。我们用光学显微镜和扫描电子显微镜（SEM）检查了内共生体的形态，并使用小亚基（SSU）rDNA序列推断它们的系统发育关系。在宿主“ sp. Quadra”中，我们发现了两种不同的 物种； 。cf. 仅栖息在前肠，而 。n. sp. 栖息在中肠到后肠，这反映了空间生态位划分。n. sp. 也存在于宿主 中，该宿主还寄生有无口纤毛虫 n. gen. et sp. cf. ，而 。n. gen. et sp. 在另一个宿主物种中不存在，这表明宿主特异性。这个系统为探索宿主 - 内共生体相互作用以及内共生体之间竞争的各个方面提供了一个有趣的机会。
