Kim Miran, Drumm Kirstine, Daugbjerg Niels, Hansen Per J
Marine Biological Section, Department of Biology, University of Copenhagen Helsingør, Denmark.
Marine Biological Section, Department of Biology, University of Copenhagen Copenhagen, Denmark.
Front Microbiol. 2017 Mar 21;8:423. doi: 10.3389/fmicb.2017.00423. eCollection 2017.
The marine mixotrophic ciliate is known to acquire chloroplasts, mitochondria, nucleomorphs, and nucleus from its cryptophyte prey, particularly from species in the genera, and . The sequestered prey nucleus and chloroplasts are considered to support photosynthesis of . In addition, recent studies have shown enlargement of the retained prey nucleus in starved and have inferred that enlargement results from the fusion of ingested prey nuclei. Thus far, however, little is known about the mechanism underlying the enlargement of the prey nucleus in . Here, we conducted starvation and refeeding studies to monitor the fate of prey nuclei acquired by when feeding on and to explore the influence of the retained prey nucleus on photosynthesis of . Results indicate that enlargement of the prey nucleus does not result from fusion of nuclei. Furthermore, the enlarged prey nucleus does not appear to divide during cell division of . The presence of a prey nucleus significantly affected photosynthetic performance of , while the number of retained chloroplasts had little influence on rate of carbon fixation. We interpret results within the context of a model that considers the dynamics of ingested prey nuclei during division of .
已知海洋混合营养型纤毛虫会从其隐藻猎物中获取叶绿体、线粒体、核质体和细胞核，尤其是来自属和属中的物种。被隔离的猎物细胞核和叶绿体被认为支持的光合作用。此外，最近的研究表明，饥饿状态下保留的猎物细胞核会增大，并推断这种增大是由摄入的猎物细胞核融合所致。然而，迄今为止，对于中猎物细胞核增大的潜在机制知之甚少。在这里，我们进行了饥饿和再投喂研究，以监测以 为食时获取的猎物细胞核的命运，并探讨保留的猎物细胞核对光合作用的影响。结果表明，猎物细胞核的增大并非由细胞核融合导致。此外，增大的猎物细胞核在细胞分裂过程中似乎不会分裂。猎物细胞核的存在显著影响了的光合性能，而保留的叶绿体数量对碳固定速率影响不大。我们在一个考虑了在分裂过程中摄入的猎物细胞核动态变化的模型背景下解释这些结果。
