Chloroplast Ultrastructure and Photosynthetic Response of the Dinoflagellate Akashiwo sanguinea Throughout Infection by Amoebophrya sp.
Chloroplast Ultrastructure and Photosynthetic Response of the Dinoflagellate Akashiwo sanguinea Throughout Infection by Amoebophrya sp.
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DOI：
10.3389/fmars.2021.742498
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发表时间：
2021-11
期刊：
影响因子：
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通讯作者：
Tiantian Chen;Yun Liu;Zhangxi Hu;Shu-qun Song;Caiwen Li
中科院分区：
文献类型：
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作者：
Tiantian Chen;Yun Liu;Zhangxi Hu;Shu-qun Song;Caiwen Li
内寄生甲藻Amoebophrya感染许多海洋甲藻，包括有毒和有害的藻华形成物种。这种寄生虫杀死其宿主，并被认为是限制沿海沃茨甲藻水华消亡的决定因素。以往的研究主要集中在变形虫的发生、流行和多样性方面，而对寄生虫与宿主之间的相互作用的关注有限。在此，一种阿米巴属（Amoebophrya sp.-建立了中国近海沃茨赤潮血吸虫共培养体系，系统研究了赤潮血吸虫感染过程中的形态、生理和转录变化。寄生甲藻的传染性很强，当甲藻孢子与宿主比为10：1时，感染率高达85.83%。感染的宿主细胞最终死亡，并释放约370个甲藻孢子/细胞。寄主细胞的核结构被阿米巴虫侵染后迅速降解，被寄生的寄主细胞的叶绿体保持完整，直到寄生虫几乎充满整个细胞结构。然而，感染的培养物表现出持续但较低的光合性能水平（对照培养物的1.64%），光合相关基因显著下调。这些研究结果有助于更好地理解寄生虫-宿主相互作用的生物学基础，这将有助于进一步阐明寄生甲藻在海洋生态系统中的生态学意义。
The endoparasitic dinoflagellate Amoebophrya infects a number of marine dinoflagellates, including toxic and harmful algal bloom-forming species. The parasite kills its host and has been proposed to be a determining factor in the demise of dinoflagellate blooms in restricted coastal waters. Previous studies have mainly focused on the occurrence, prevalence, and diversity of Amoebophrya, while the interactions between the parasite and its host have received limited attention. Herein, an Amoebophrya sp.-Akashiwo sanguinea co-culture was established from Chinese coastal waters, and morphological, physiological, and transcriptional changes throughout an infection cycle of the parasite were systemically studied. The parasitic dinoflagellate was very infectious, resulting in an infection rate up to 85.83% at a dinospore:host ratio of 10:1. Infected host cells died eventually and released approximately 370 dinospores/cell. The host nuclear structures were rapidly degraded by Amoebophrya infection, and the chloroplasts of parasitized host cells remained intact until the parasite filled the almost entire cell structure. Nevertheless, infected cultures showed sustained but lower levels of photosynthetic performance (∼64% of control cultures), and the photosynthesis-related genes were significantly down-regulated. These findings provide a better understanding of the biological basis of the complex parasite-host interactions, which will be helpful to further elucidate the ecological significance of parasitic dinoflagellates in marine ecosystems.