ABSTRACT

Metacyclogenesis is one of the most important processes in the life cycle of Trypanosoma cruzi. In this stage, noninfective epimastigotes become infective metacyclic trypomastigotes. However, the transcriptomic changes that occur during this transformation remain uncertain. Illumina RNA-sequencing of epimastigotes and metacyclic trypomastigotes belonging to T. cruzi DTU I was undertaken. Sequencing reads were aligned and mapped against the reference genome, differentially expressed genes between the two life cycle stages were identified, and metabolic pathways were reconstructed. Gene expression differed significantly between epimastigotes and metacyclic trypomastigotes. The cellular pathways that were mostly downregulated during metacyclogenesis involved glucose energy metabolism (glycolysis, pyruvate metabolism, the Krebs cycle, and oxidative phosphorylation), amino acid metabolism, and DNA replication. By contrast, the processes where an increase in gene expression was observed included those related to autophagy (particularly Atg7 and Atg8 transcripts), corroborating its importance during metacyclogenesis, endocytosis, by an increase in the expression of the AP-2 complex subunit alpha, protein processing in the endoplasmic reticulum and meiosis. Study findings indicate that in T. cruzi metacyclic trypomastigotes, metabolic processes are decreased, and expression of genes involved in specific cell cycle processes is increased to facilitate transformation to this infective stage.

摘要

元周期发生是克鲁斯锥虫生命周期中最重要的过程之一。在这个阶段，非感染性表鞭鞭毛虫变成了感染性的环环类拟鞭毛体。但是，在这种转化过程中发生的转录组变化仍然不确定。属于克鲁斯锥虫的表鞭鞭毛虫和亚环类锥鞭毛鞭虫的Illumina RNA测序进行了DTUI。将测序读物比对并对照参考基因组作图，鉴定两个生命周期阶段之间差异表达的基因，并重建代谢途径。在表鞭鞭毛虫和间环类锥鞭毛虫之间，基因表达差异显着。在元周期发生过程中大多数被下调的细胞途径涉及葡萄糖能量代谢（糖酵解，丙酮酸代谢，克雷布斯循环和氧化磷酸化），氨基酸代谢和DNA复制。相比之下，观察到基因表达增加的过程包括与自噬相关的过程（尤其是Atg7和Atg8转录物），从而通过增加AP-2复杂亚基α的表达来证实其在代谢，内吞作用中的重要性。内质网和减数分裂中的蛋白质加工。研究结果表明克鲁维氏锥虫的变态锥甲鞭毛虫，减少了代谢过程，并增加了参与特定细胞周期过程的基因表达，以促进向该感染阶段的转化。