Fig. 2.

Localization of Defb15 protein in rat epididymis. a The sensitivity and specificity of rabbit polyclonal antibody towards Defb15 were verified by western blotting. b Protein extracts from various tissues were analyzed by western blotting analysis. GAPDH and β-actin were used to assess protein loading. c Immunohistochemical staining shows the expression pattern of Defb15 protein in the whole epididymis in a 120-day-old rat (bar 4 mm). d Magnified photographs of individual fields of c: a initial segment; b, c caput; d corpus; e cauda. Preimmune serum under the same conditions showed the background level of immunoreactivity (bars 50 μm). e Western blot analysis of Defb15 protein in total protein extracts of sperm from the caput, corpus and cauda regions of the epididymis. β-Actin was used for loading control. f Localization of Defb15 protein (FITC-labeled) on the spermatozoa by indirect immunofluorescence assays. Positive Defb15 immunoreactivity is seen at the head of sperm from the caput region, but no signal is seen on sperm from the corpus or cauda regions of the epididymis (bars 10 μm). g Refined localization of Defb15 (TRITC-labeled) on the caput sperm surface. The acrosome of the sperm was stained by Alexa Fluor 488-conjugated lectin PNA, and sperm DNA was stained with DAPI (bars 5 μm)