Sabaneyeva Elena, Kursacheva Ekaterina, Vizichkanich Galina, Lebedev Dmitrii, Lebedeva Natalia
Department of Cytology and Histology, Faculty of Biology, Saint-Petersburg State University, Saint-Petersburg, Russian Federation.
A.G. Knorre Department of Histology and Embryology, Saint-Petersburg State Pediatric Medical University, Saint-Petersburg, Russian Federation.
Protoplasma. 2025 May;262(3):595-607. doi: 10.1007/s00709-024-02025-x. Epub 2025 Jan 2.
Ciliates often form symbiotic associations with other microorganisms, both prokaryotic and eukaryotic. We are now starting to rediscover the symbiotic systems recorded before molecular analysis became available. Here, we provide a morphological and molecular characterization of a symbiotic association between the ciliate Paramecium tritobursaria and the yeast Rhodotorula mucilaginosa (syn. Rhodotorula rubra) isolated from a natural population. This symbiotic system demonstrates certain similarities with the symbiotic system formed by P. bursaria and its conventional endosymbionts, the zoochlorellae. Experimental infections of the endosymbiont-free P. tritobursaria and Paramecium deuterobursaria cell lines with R. mucilaginosa demonstrated that the yeast infectivity is concentration-dependent, with ciliates digesting part of the yeast cells. The endosymbiotic yeast may serve as a food reserve, providing starvation stress tolerance to the host. Since R. mucilaginosa is currently regarded as a pathogen causing opportunistic infections in immunocompromised humans, our finding gives further support to the vision that ciliates can harbor potential human pathogens and can be a vector for their dissemination.
纤毛虫经常与其他微生物形成共生关系，包括原核生物和真核生物。在分子分析出现之前，我们现在开始重新发现之前记录的共生系统。在这里，我们对从自然种群中分离出的纤毛虫三角草履虫和酵母粘红酵母（同义词：深红酵母）之间的共生关系进行了形态学和分子特征描述。这个共生系统与草履虫和其传统内共生体绿藻形成的共生系统有一定相似之处。用粘红酵母对无内共生体的三角草履虫和双核草履虫细胞系进行实验感染表明，酵母的感染性是浓度依赖性的，纤毛虫会消化部分酵母细胞。内共生酵母可以作为食物储备，为宿主提供对饥饿胁迫的耐受性。由于粘红酵母目前被认为是一种在免疫功能低下的人类中引起机会性感染的病原体，我们的发现进一步支持了纤毛虫可以携带潜在人类病原体并可能成为其传播载体的观点。
