FIGURE 3.

Sustained high PTP1B activity in ob/ob mouse spermatozoa impairs the SNARE complex reassembly under the stimulation with progesterone. A, schematic illustration of cis-SNARE complex disassembly and the reassembly of trans-SNARE complexes in sperm during the AR. B, double staining of VAMP2 (sensitive to TeTx) and SNAP25 (resistant to TeTx) in capacitated spermatozoa of WT and ob/ob mice after treatment with or without the combination of PTP1B inhibitor, TeTx, or progesterone for 10 min. Asterisks indicate the cells in which the VAMP2 immunostaining signals at acrosomal region are absent. Arrows indicate the cells that have intact VAMP2 immunostaining signals at the acrosomal region. DIC, differential interference contrast. **, p < 0.01, n = 5; a total of about 200 spermatozoa heads were counted to calculate two above patterns. Scale bar, 3 μm. Error bars, S.D.