Figure 4. Motility is dispensable for infection and pathogenesis.

(A) Parasitemias of mice infected with K/R point mutants. Mice were maintained without tetracycline (solid lines, − Tet) or with tetracycline (dashed lines, + Tet) in the drinking water. Mice were infected at day 0 and parasitemia was determined beginning three days post infection (dpi). Representative data are shown for two − Tet and + Tet mice from a total of 18 −Tet and 20 +Tet infections. Typically, mice exhibited a single wave of parasitemia (triangles) but one mouse in each group showed two waves (circles). (B) Survival curves for all K/R-infected mice, maintained without tetracycline (−Tet, solid lines, n = 18) or with tetracycline (+Tet, dashed line, n = 20) in the drinking water. Any differences were not significant (p = 0.0750). One mouse in each group did not show detectable parasitemia. (C) Western blot of total protein prepared from K/R point mutants grown in culture (culture) or purified from infected mice (mice) maintained with (+) or without (−) Tet. Parasites from mice were taken at parasitemia peak 1 or peak 2 as indicated. Blots were probed with antibody against VSG221 or β-tubulin as a loading control. (D–F) Uninfected mice (uninf) or mice infected with K/R point mutants maintained without (− Tet) or with (+ Tet) tetracycline, were examined for total body weight (D) anemia (E) and spleen weight (F). Body weight and spleen weight were determined seven dpi. (Uninfected mice n = 3; mice infected with K/R mutants − Tet n = 4; + Tet n = 6.). Anemia was assessed seven dpi. (Uninfected mice n = 4; − Tet infections n = 5; + Tet infections n = 7.) Error bars show standard deviation.