Decrease in STEVOR expression is associated with an increase in deformability of immature GIEs. (A) Immunofluorescence analysis of STEVOR expression in stage III and stage IV GIEs from the B10, H4, and A12 clones. GIEs were stained with a pool of mouse polyclonal antibodies directed against STEVOR proteins followed by anti–mouse Alexa-488–conjugated IgG. Signal intensity was analyzed by ImageJ Version 6 on at least 30 pictures taken under identical exposition conditions for each clone. Bars represent 2 μm. (B) Western blot analysis of STEVOR expression in stage III and stage V GIEs from the wild-type and the SFM parasites. Immunoblots were probed with a pool of mouse polyclonal antibodies directed against STEVOR proteins and with a mAb directed against HSP70. (C) Retention in microsphilters of stages II, III, IV, and V GIEs from the B10 (light gray), H4 (dark gray), and A12 (red) clones. ***Highly significant differences in retention rates (P < .01). Outliers are shown as open circles.