Cell cycle and cleavage events during in vitro cultivation of bloodstream forms of Trypanosoma lewisi, a zoonotic pathogen
Cell cycle and cleavage events during in vitro cultivation of bloodstream forms of Trypanosoma lewisi, a zoonotic pathogen
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人畜共患病原体刘易斯锥虫血流体外培养过程中的细胞周期和裂解事件
DOI：
10.1080/15384101.2019.1577651
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发表时间：
2019-03-04
期刊：
影响因子：
4.3
通讯作者：
Lun，Zhao-Rong
中科院分区：
文献类型：
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作者：
Zhang，Xuan;Li，Su-Jin;Lun，Zhao-Rong
刘易斯锥虫（Herpetosoma）是一种全球分布的大鼠锥虫，目前被认为是一种人畜共患病原体；然而，缺乏对细胞周期中发生的形态学事件的详细了解。本研究旨在研究路易斯锥虫（T. lewisi）在体外培养过程中的细胞周期形态和分裂事件。通过在37℃条件下建立离体培养，可以观察到不同的细胞形态和阶段。我们对李氏菌增殖过程中的形态学事件进行了定量分析。我们确定的生成时间为12.14±0.79小时，与体内（12.21±0.14小时）相似。我们还发现，该寄生虫的发育状态存在两种不同的细胞周期，并具有双向转化联系，这与之前在T. lewis中看到的多重分裂模式形成了对比。我们量化了细胞周期阶段的时间（G1n, 0.56 U; Sn, 0.14 U; G2n, 0.16 U； M, 0.06 U； C, 0.08 U; G1k, 0.65 U; Sk, 0.10 U; G2k, 0.17 U； D, 0.03 U； A, 0.05 U）和它们的形态特征，特别是关于着丝体(s)和核/核的位置。有趣的是，我们发现刘易斯锥虫的核合成起始和分离都发生在着丝体之前，与布鲁氏锥虫和克氏锥虫的复制顺序不同，这表明刘易斯锥虫有不同的细胞周期控制机制。我们描述了T. lewis细胞周期中的形态学事件，并提供证据支持两个不同的细胞周期的存在，并在它们之间进行双向转化。这些结果为该寄生虫及其相关物种的分化和进化提供了见解。
ABSTRACT Trypanosoma (Herpetosoma) lewisi is a globally distributed rat trypanosome, currently considered as a zoonotic pathogen; however, a detailed understanding of the morphological events occurring during the cell cycle is lacking. This study aimed to investigate the cell cycle morphology and cleavage events of Trypanosoma lewisi (T. lewisi) during in vitro cultivation. By establishing in vitro cultivation of T. lewisi at 37°C, various cell morphologies and stages could be observed. We have provided a quantitative analysis of the morphological events during T. lewisi proliferation. We confirmed a generation time of 12.14 ± 0.79 hours, which is similar to that in vivo (12.21 ± 0.14 hours). We also found that there are two distinct cell cycles, with a two-way transformation connection in the developmental status of this parasite, which was contrasted with the previous model of multiple division patterns seen in T. lewisi. We quantified the timing of cell cycle phases (G1n, 0.56 U; Sn, 0.14 U; G2n, 0.16 U; M, 0.06 U; C, 0.08 U; G1k, 0.65 U; Sk, 0.10 U; G2k, 0.17 U; D, 0.03 U; A, 0.05 U) and their morphological characteristics, particularly with respect to the position of kinetoplast(s) and nucleus/nuclei. Interestingly, we found that both nuclear synthesis initiation and segregation in T. lewisi occurred prior to kinetoplast, different to the order of replication found in Trypanosoma brucei and Trypanosoma cruzi, implicating a distinct cell cycle control mechanism in T. lewisi. We characterized the morphological events during the T. lewisi cell cycle and presented evidence to support the existence of two distinct cell cycles with two-way transformation between them. These results provide insights into the differentiation and evolution of this parasite and its related species.