Fig. 4
Progesterone and cumulus-oocyte complexes (COCs) induce sperm release from suLeX immobilized on coverslips. (a) Binding density (per mm2) to suLeX-coverslips after incubation of 1 × 106 sperm/mL for 30 min, followed by incubation for 1 h with control Modified Tris-buffered medium (mTBM), capacitating mTBM (containing 2.5 mM caffeine), capacitating mTBM supplemented with 800 nm progesterone (P4), and capacitating mTBM supplemented with 4 mM 4-aminopyridine (4-AP). (b) Binding density to suLeX-coverslips after incubation of 0.25 × 106 sperm/mL for 30 min, followed by 5 h with live COCs or denatured COCs. The error bars indicate mean ± SEM. Different letters indicate p < 0.05. (c) Representative microscopic images of sperm immobilized on suLeX-coverslips and cultured with COCs. Scale bar = 50 μm. Arrowheads show sperm bound to cumulus cells.
