Figure 1. Characterization of CATSPER2‐deficient human sperm.

• A
  Representative Ca²⁺ signals in sperm from a patient with deafness‐infertility syndrome lacking functional CatSper channels (CATSPER2 ^−/−; red) and a healthy donor (black), evoked by progesterone, PGE1, NH₄Cl, or ionomycin. NH₄Cl increases the intracellular pH. Bar graph: Amplitudes (n = 4; mean ± SD) of Ca²⁺ signals in CATSPER2 ^−/− sperm.
• B
  Representative monovalent CatSper currents in CATSPER2 ^−/− sperm (blue, green, orange, purple, brown) and in sperm from a healthy donor (black), and corresponding current‐voltage relationship (right). The membrane voltage was stepped from −100 to +100 mV in increments of 10 mV from a holding potential of −80 mV.
• C
  Outward and inward current amplitudes (mean ± SD) at + 100 mV and ‐100 mV, respectively, in CATSPER2 ^−/− sperm (color code: panel B) and sperm from healthy donors (black).
• D, E
  Representative immunocytochemical staining of control sperm from healthy donors and CATSPER2 ^−/− sperm from DIS patients using antibodies directed against CatSper 3 (D) or CatSper 4 (E); DNA was labeled with DAPI (blue). Scale bars represent 10 μm.
• F
  3D‐STORM image in xy projection of sperm from a healthy donor labeled with the anti‐CatSper 3 antibody (left). Axial projection of the boxed region (right). Scale bars represent 5 μm in xy projections and 200 nm in axial projections.
• G
  3D‐STORM images in xy projection of CATSPER2 ^−/− sperm (left) labeled with the anti‐CatSper 3 (upper panel) or anti‐CatSper 4 (lower panel) antibody. Axial projection of the boxed regions (right). Scale bars represent 5 μm in xy projections and 200 nm in axial projections.