Cell cycle and cleavage events during in vitro cultivation of bloodstream forms of Trypanosoma lewisi, a zoonotic pathogen

Zhang, X; Li, S-J; Li, Z; He, CY; Hide, G; Lai, D-H; Lun, Z-R

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 nuclear replication in T. lewisi occurred prior to kinetoplast replication, 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.

Keywords: Trypanosoma lewisi, Cell cycle, In vitro, Multiplication, Division, Zoonotic pathogen

Citation

Zhang, X., Li, S.-J., Li, Z., He, C., Hide, G., Lai, D.-H., & Lun, Z.-R. (2019). Cell cycle and cleavage events during in vitro cultivation of bloodstream forms of Trypanosoma lewisi, a zoonotic pathogen. Cell Cycle, 18(5), 552-567. https://doi.org/10.1080/15384101.2019.1577651

• Journal Article Type: Article
• Acceptance Date: Jan 29, 2019
• Online Publication Date: Feb 2, 2019
• Publication Date: Feb 20, 2019
• Deposit Date: Feb 21, 2019
• Publicly Available Date: Feb 2, 2020
• Journal: Cell Cycle
• Print ISSN: 1538-4101
• Publisher: Taylor and Francis
• Volume: 18
• Issue: 5
• Pages: 552-567
• DOI: https://doi.org/10.1080/15384101.2019.1577651
• Publisher URL: https://doi.org/10.1080/15384101.2019.1577651
• Related Public URLs: https://www.salford.ac.uk/environment-life-sciences/our-staff/els-academics/geoff-hide; https://www.tandfonline.com/toc/kccy20/current