Figure 1. The introduction of UCH-L1 inhibitor LDN-57444 markedly reduced proteasome activity and inhibited mouse oocyte maturation.

Mouse oocytes were matured for 18 h in the presence of DMSO (control) or LDN-57444 (10, 20 µM), followed by the measurement of UCH-L1 protein level (A), proteasome activity (B), first polar body extrusion rate (C). **P<0.01. ***P<0.001.