Figure 9. Evaluation of the content of the arginine (Arg)-X-Arg-X-X-phospho (P)-serine (Ser)/threonine (Thr) motif of proteins recognized by the respective antibody. Spermatozoa were incubated in either Biggers-Whitten-Whittingham (BWW) medium (white bars) or fetal cord serum ultrafiltrate (FCSu) (black bars) after cell pretreatment with either LY294002 (2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one) (LY, at 3 and 30 µmol/L) or wortmannin (W, at 10 and 100 nmol/L). Following immunoblotting, major proteins recognized by the anti–Arg-X-Arg-X-X-P-Ser/Thr antibody were further analyzed by densitometry as stated in "Materials and Methods." (A) The densitometric assessments of the 140-kd protein, (B) the 110-kd protein, (C) the 97-kd protein, (D) the 80-kd protein, and (E) the 70-kd protein are shown. Results are mean ± SEM of 4 determinations performed on sperm samples from different donors. ^* indicates that a value is different from that of control spermatozoa (To).