The differentiation of cellular structure during encystment in the soil hypotrichous ciliate Australocirrus cf. australis (Protista, Ciliophora)
The differentiation of cellular structure during encystment in the soil hypotrichous ciliate Australocirrus cf. australis (Protista, Ciliophora)
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土壤下毛纤毛虫 Australocirrus cf. 包囊过程中细胞结构的分化。
DOI：
10.1080/19768354.2016.1262896
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发表时间：
2017-01-01
影响因子：
2.9
通讯作者：
Gu, Fukang
中科院分区：
文献类型：
--
作者：
Li, Qili;Sun, Qianqian;Gu, Fukang
纤毛虫能够形成休眠的包囊，作为应对压力环境因素的一种生存策略。对包囊过程中细胞结构特征的研究可能为进一步了解细胞模式的调控机制提供有用的信息，并为纤毛虫的系统发育提供新的线索。用扫描和透射电子显微镜观察了土壤纤毛虫成囊过程中细胞的超微结构。澳大利亚人。纤毛脱分化现象首次被发现。纤毛轴首先缩短，剩下的纤毛，包括基底体和纤维环篮，收缩到细胞质中，被自噬空泡包围，然后逐渐消化。在成熟休眠包囊中观察到大量的自噬空泡。自噬可能不仅对包囊化过程中细胞结构的分化是必要的，而且对于维持休眠阶段的基本生命活动也可能是重要的。澳大利亚卷须草cf.南方原虫形成动粒吸收囊壁，囊壁分为四层：外囊、中囊、内囊和颗粒层。纤毛虫的纤毛吸收状态和囊壁的层数与其他尖毛纤毛虫一致。然而，包囊过程中两个大核结节不融合的现象并不常见。此外，该物种中囊中的八面体颗粒表现出与同类不同的形态。
Ciliates are able to form resting cysts as a survival strategy in response to stressful environmental factors. Studies on the characteristics of cellular structure during encystment may provide useful information for further understanding of the regulatory mechanism of cellular patterns and supply new clues regarding the phylogeny of ciliates. Scanning and transmission electron microscopies were used to observe the ultrastructure of cells during encystment of the soil ciliate Australocirrus cf. australis. The dedifferentiation of ciliature was revealed for the first time. Ciliary shafts first shortened, and the remaining ciliature, including basal bodies and the fibrillar cirral basket, retracted into the cytoplasm and was surrounded by the autophagic vacuoles and then gradually digested. A large number of autophagic vacuoles were observed in mature resting cysts. Autophagy might not only be necessary for the differentiation of cellular structures during encystment but might also be important to sustain the basic life activities in the resting stage. Australocirrus cf. australis formed a kinetosome-resorbing cyst and contained four layers in the cyst wall: the ectocyst, mesocyst, endocyst and granular layer. The ciliature resorbing state and the number of layers in the cyst wall were consistent with those found in other oxytrichous ciliates. However, the phenomenon wherein the two macronuclear nodules are not fused during encystment is not commonly observed among oxytrichids. Additionally, the octahedral granules in the mesocyst of this species exhibit different morphology from the congeners.