Revisiting the Trypanosoma cruzi metacyclogenesis: morphological and ultrastructural analyses during cell differentiation.
Revisiting the Trypanosoma cruzi metacyclogenesis: morphological and ultrastructural analyses during cell differentiation.
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DOI：
10.1186/s13071-018-2664-4
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发表时间：
2018-02-06
影响因子：
3.2
通讯作者：
Cavalcanti DP
中科院分区：
文献类型：
--
作者：
Gonçalves CS;Ávila AR;de Souza W;Motta MCM;Cavalcanti DP
克氏锥虫使用几种策略在不同的宿主中生存。该寄生虫生命周期的关键步骤是metacylogenesis，它涉及各种形态，生化和遗传变化，诱导非致病性附体向致病性metacyclic trypmasastigotes分化。在球胞发生过程中，克氏锥虫表现出不同的形态和超微结构特征，这些特征尚未被完全描述。我们使用不同的显微镜技术对元胞发生进行了时间描述，结果鉴定出克氏锥虫的三种中间形式：中间体I、II和III。这种分类基于形态和超微结构方面，如与细胞核有关的着丝质体位置，着丝质体形状和kDNA拓扑结构。此外，我们认为元环锥乳突虫来源于已经脱离底物的中间形式。我们还发现，只有在这种结构向细胞体后部重新定位后，才会发生着丝体形态和kDNA排列的变化。这些变化发生在分化的后期。相比之下，核形状的改变在元胞形成开始时就开始了，而核超微结构的变化，如核仁的丢失，只在分化后期才观察到。最后，我们发现不同克氏菌形态的kDNA网络呈现出不同的DNA拓扑模式。我们对克氏T. crozi细胞元胞发生的研究揭示了这个有趣的细胞分化过程的形态学和超微结构的重要方面。这项研究扩大了我们对这种寄生虫迷人的生命周期的理解。它还强调了克氏锥虫作为研究细胞、分子和进化生物学各个方面的重要和令人兴奋的模型系统的研究。
Trypanosoma cruzi uses several strategies to survive in different hosts. A key step in the life-cycle of this parasite is metacyclogenesis, which involves various morphological, biochemical, and genetic changes that induce the differentiation of non-pathogenic epimastigotes into pathogenic metacyclic trypomastigotes. During metacyclogenesis, T. cruzi displays distinct morphologies and ultrastructural features, which have not been fully characterized. We performed a temporal description of metacyclogenesis using different microscopy techniques that resulted in the identification of three intermediate forms of T. cruzi: intermediates I, II and III. Such classification was based on morphological and ultrastructural aspects as the location of the kinetoplast in relation to the nucleus, kinetoplast shape and kDNA topology. Furthermore, we suggested that metacyclic trypomastigotes derived from intermediate forms that had already detached from the substrate. We also found that changes in the kinetoplast morphology and kDNA arrangement occurred only after the repositioning of this structure toward the posterior region of the cell body. These changes occurred during the later stages of differentiation. In contrast, changes in the nucleus shape began as soon as metacyclogenesis was initiated, while changes in nuclear ultrastructure, such as the loss of the nucleolus, were only observed during later stages of differentiation. Finally, we found that kDNA networks of distinct T. cruzi forms present different patterns of DNA topology. Our study of T. cruzi metacyclogenesis revealed important aspects of the morphology and ultrastructure of this intriguing cell differentiation process. This research expands our understanding of this parasite’s fascinating life-cycle. It also highlights the study of T. cruzi as an important and exciting model system for investigating diverse aspects of cellular, molecular, and evolutionary biology.