Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada.
Exp Suppl. 2022;114:91-114. doi: 10.1007/978-3-030-93306-7_4.
Microsporidia are a large phylum of obligate intracellular parasites that infect an extremely diverse range of animals and protists. In this chapter, we review what is currently known about microsporidia host specificity and what factors influence microsporidia infection. Extensive sampling in nature from related hosts has provided insight into the host range of many microsporidia species. These field studies have been supported by experiments conducted in controlled laboratory environments which have helped to demonstrate host specificity. Together, these approaches have revealed that, while examples of generalist species exist, microsporidia specificity is often narrow, and species typically infect one or several closely related hosts. For microsporidia to successfully infect and complete their life cycle within a compatible host, several steps must occur, including spore germination, host cell invasion, and proliferation of the parasite within the host tissue. Many factors influence infection, including temperature, seasonality, nutrient availability, and the presence or absence of microbes, as well as the developmental stage, sex, and genetics of the host. Several studies have identified host genomic regions that influence resistance to microsporidia, and future work is likely to uncover molecular mechanisms of microsporidia host specificity in more detail.
微孢子虫是一大类专性细胞内寄生的原生动物，感染范围极广，包括各种动物和原生生物。在本章中，我们将回顾目前已知的微孢子虫宿主特异性以及影响微孢子虫感染的因素。从相关宿主中进行的广泛野外采样为许多微孢子虫物种的宿主范围提供了深入了解。这些野外研究得到了在受控实验室环境中进行的实验的支持，这些实验有助于证明宿主特异性。这些方法共同表明，虽然存在一般物种的例子，但微孢子虫的特异性通常很窄，物种通常感染一个或几个密切相关的宿主。为了使微孢子虫在相容的宿主中成功感染并完成其生命周期，必须发生几个步骤，包括孢子萌发、宿主细胞入侵以及寄生虫在宿主组织内的增殖。许多因素会影响感染，包括温度、季节性、营养物质的可利用性以及微生物的存在与否，以及宿主的发育阶段、性别和遗传特性。一些研究已经确定了影响宿主对微孢子虫抗性的宿主基因组区域，未来的工作可能会更详细地揭示微孢子虫宿主特异性的分子机制。
