Transcriptional remodeling during metacyclogenesis in Trypanosoma cruzi I

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.

KEYWORDS:

• Trypanosoma cruzi
• metacyclic trypomastigotes
• epimastigotes
• transcriptomic
• pathways

Acknowledgments

We thank Philipp Shwabl for his assistance in bioinformatics analysis.

Disclosure statement

The authors declare there are no competing interests.

Author contributions

LCS performed the biological analysis, RNA extraction from metacyclic trypomastigotes and epimastigotes, performed the bioinformatics analysis, and drafted the manuscript. GV contributed to generating the T. cruzi strain. FG contributed to designing the study. LAM assisted with manuscript drafting. JDR designed the study, coordinated the biological and bioinformatics analyses, and wrote the manuscript. All authors read and approved the final manuscript.

Data availability

All data employed in this paper are available in the European Nucleotide Archive (ENA) under PRJEB33521 study accession (https://www.ebi.ac.uk/ena/data/view/PRJEB33521).

Supplementary materials

Supplemental data for this article can be accessed here.

Additional information

Funding

We thank the Departamento Administrativo de Ciencia, Tecnología e Innovación COLCIENCIAS for funding the project 120465843375, contract 063-2015 (http://www.colciencias.gov.co/node/1119) for FG, GAV, and JDR. The funders played no role in the study design, data collection, and analysis, publishing decision, or manuscript preparation. We thank DIRECCIÓN ACADÉMICA (Becas de pasantías doctorales) for financing the scholarship for LCS. Juan David Ramírez González, PhD. is a Latin American fellow in the Biomedical Sciences, supported by The Pew Charitable Trusts.