Figure 4. | Toxoplasma gondii F-actin forms an extensive filamentous network required for material exchange and parasite maturation

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Toxoplasma gondii F-actin forms an extensive filamentous network required for material exchange and parasite maturation

Figure 4.

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University of Glasgow, United Kingdom; Cancer Research United Kingdom Beatson Institute, United Kingdom; University of Vermont, United States
Figure 4.
Download figureOpen in new tabFigure 4. Phenotypic analysis of parasite expressing Cb-Halo.

(A) Left. Growth assay of indicated parasites. After 5 days growth no significant difference in growth rates can be observed. Right. Representative image of plaque area size created. Scale bar, 100 μm. (B) Replication rates between Cb-Halo and RH parasites are comparable. Indicated parasites were inoculated on HFF cells and number of parasites/vacuole was determined. (C) Invasion rates are not significantly different between RH and Cb-Halo expressing parasites. Parasites were allowed to invade for 1 hr, before non-invaded parasites were removed. (D) Penetration time of parasites was determined using time-lapse analysis. Both RH and Cb-Halo expressing parasites are capable to invade the host cell within 30 s. In some cases slower parasites can be detected, although on average the difference is insignificant. n = 22 independent events. (E) No differences in egress could be detected between RH and Cb-Halo parasites. Egress was triggered using Calcium Ionopore A23187 and the number of egress events was determined after 10 min. (F) Trail deposition assay comparing gliding rates between RH and Cb-Halo. Cb-Halo parasites form slightly more trails (*p<0.05). (G,H) Comparison of gliding motility between RH and Cb-Halo. Whereas average run length (G) is identical, parasites expressing Cb-Halo demonstrate slower gliding speeds for helical and circular motility. Parasites were tracked with Fiji wrMTrck software. N = 20 individual events for each condition. All assays were conducted in triplicates. Datasets were compared using two-tailed Student’s t-test. Error bars for A,B,C,E,F represent S.E.M from three independent, biological replicates. Error bars for D, G, H represent 95 % CI. *p<0.05, ****p<0.0001. For source data see supplementary information (Figure 4—source data 1).

DOI: http://dx.doi.org/10.7554/eLife.24119.011