Figure 3.

Phase-contrast microscopy of extracellular wild-type (A) and His28Gln mutant parasites (B) illustrates that Toxoplasma expressing the His28Gln mutation are thinner and longer and they show an increased frequency of septation defects. (C–E) Projections of wild-type (C) and His28Gln mutant parasites (E) indicate that His28Gln mutant parasites have longer microtubules. These three-dimensional projections were created by collecting Z-series images of newly invaded parasites stained with a Toxoplasma-specific tubulin antibody. The images were processed with Zeiss deconvolution software. An overlay of the wild-type parasite projection (green) on the His28Gln mutant parasite projection (red) illustrates the increased subpellicular microtubule length in the mutant parasites (D).