Rescue of phenotypical abnormality in ACRBP-deficient mice. Cauda epididymal sperm of ACRBP-deficient mice (KO) expressing the Acrbp-W-EGFP (KOW-TG) or Acrbp-V5 transgene (KOV5-TG) were divided into four types (types 1, 2, 3, and 4) based on the acrosomal and nuclear morphologies, as described in Fig. 4A. KOW-TG and KOV5-TG sperm were stained with Alexa Fluor 568-conjugated PNA and Hoechst 33342, randomly selected (200 cells per each assay) and counted. For comparison, the rate of each type of KO sperm is shown (Fig. 4A). WT-like, sperm showing the morphology comparable to that of wild-type sperm.