Immunohistochemical localization of Wap65-2 in carp testis (A), spermatic duct (B), and liver (C). Bars = 10 μm. A Strong signal for Wap65-2 is present in some cysts that contain spermatogonia A (SgA) and spermatogonia B (SgB), as well as in Leydig cells (arrowheads). At higher magnification (bottom image), note the strong signal around the epithelium of blood vessels (Bv). No immunopositive staining is observed in primary (Spc1) and secondary spermatocytes (Spc2), spermatids (Spt), and Sertoli cells (arrows). Immunonegative spermatozoa (Sz) are clearly visible. B In the spermatic duct, there is weak to moderate signal for Wap65-2 in columnar secretory cells (black arrows) and stromal cells (asterisks). Positive staining from luminal epithelium is visible near spermatozoa. C In the liver cells, there is a positive moderate signal for Wap65-2 localized to hepatocytes. Note the perinuclearly located signals (open arrows). Insets in A–C controls of testicular, spermatic duct, and liver cells when the primary antibody is omitted respectively.