Effect of Stim1/2 ablation on the ultrastructure of mouse neutrophils. (A) Perimeter and shape factor of WT and Stim1/2^−/− neutrophils fixed in suspension or after adhesion to PLL in the absence or presence of Tg (Adh+Tg). (B) Number of contact sites detected in the indicated conditions along the entire cell perimeter (left) and on the adhesive and nonadhesive membranes (middle and right). (C) cER length and gap distance at adhesive PM of WT and Stim1/2^−/− neutrophils. n = 26/19 cells with 40/60 cER sheets from two mice pairs, Mann–Whitney U test. (D) cER proportion, length, and gap distance in adherent WT and Stim1/2^−/− neutrophils treated with Tg. n = 25/25 cells with 139/209 cER sheets pfrom two mice pairs, Mann–Whitney U test. Adh: adherent; Susp, suspended.