Figure 8.
Schematic representation of the morphological alterations and the duration of the phases of the T. lewisi cell cycle. (a) Binary fission comprises the following stages: G1n/k (gap1), Sn/k (DNA synthesis period), G2n/k (gap2), M (mitosis) or D (division phase), and C (cytokinesis) or A (post-division phase) were indicated. Two equal length flagella were observed at M-phase, but the initial assembly time point for the new flagellum might occur in either Sn/k or G2n/k phase, according to related studies in T. brucei [21] or T. cruzi [23]. The duration of the cell cycle phases was listed in the table below. (b) The rosette stage undergoes multiple division and individuals can develop to either form a new rosette or to transform into transitional trypomastigotes and finally to return to fully developed trypomastigotes which can undergo binary fission. On the other hand, trypomastigotes may transform to rosette forms by means of unequal division events. (c). The duration of the cell cycle phases with respect to the nucleus and the kinetoplast. The duration of the phases of the cell cycle were calculated as described (methods, results). The phases of the nuclear events are G1n, Sn, G2n, M and C-phase, while the phases of the kinetoplast events are G1k, Sk, G2k, D and A-phase. The overall generation time is 12.14 h.