Expression of CD18 in the epididymis and its impact on epididymal function after knockout

ZHANG Yang; GENG Yao; ZHAO Jie; ZHOU Yanheng; LI Wei

doi:10.13276/j.issn.2097-1656.2026.06.013

Abstract：Objective To clarify the expression and localization of CD 18 in the epididymis of mouse,and to investigate the influence of CD18 knockout on epididymal function of mouse.Methods qRT-PCR and Western blotting were applied to investigate the expression of CD18 in the epididymis and testis of adult C57BL/6 male mice.The expression of CD 18 in the epididymis was assessed by immunohistochemistry and immunofluorescence staining.CD18-/-mice were constructed by utilizing CRISPR-Cas9 ribonucleoprotein.The forward motile sperm,pregnancy rate,and litter size of adult CD18-/-mice were counted.The tissue morphology was observed by HE staining and TUNEL staining.Results qRT-PCR and Western blotting analysis indicated that CD 18 was basically not expressed in the testes of adult male mice,but was expressed in the epididymides.Immunohistochemical staining indicated that CD 18 was expressed on the membrane of epididymal epithelium of adult mice,and was mainly concentrated in the corpus and cauda.CD18-/-mice were basically infertile.HE staining and TUNEL staining showed significantly reduced sperm count and apoptosis in cauda epididymis of CD18-/-mice.Conclusion CD18 is expressed on the cell membrane of epididymal epithelium of mouse.CD18-/-mice show decreased sperm count and apoptosis in cauda epididymis.It is speculated that the elimination of endogenous CD18 expression may have an important effect on epididymal function and male fertility.