Androgen receptor is expressed in both X- and Y-carrier human spermatozoa

Objective To quantify the amount of AR messenger RNA (mRNA) and to analyze the presence and functionality of the AR protein in X- and Y-carrier human spermatozoa. Design A molecular and cellular research study. Setting Academic research clinic and laboratories. Patient(s) Ten normozoospermic volunteers. Intervention(s) Sperm were analyzed for expression of AR mRNA and protein. The functionality of AR protein was assessed after incubation with 1 nM of synthetic androgen. Main Outcome Measure(s) Reverse-transcription polymerase chain reaction (PCR), real-time PCR, Western immunoblotting, confocal immunofluorescence, and fluorescence in situ hybridization analysis were performed. Result(s) A significant amount of AR mRNA (around 30% of that found in the testis) was found in sperm. Androgen receptor protein was found in both X- and Y-carrier spermatozoa and translocates into the nucleus in the presence of synthetic androgen. Conclusion(s) A functional AR is expressed in human sperm. In view of the fact that AR protein is found in both X- and Y-carrier spermatozoa, it most probably is translated in earlier steps of spermatogenesis and moves to Y-carrier spermatids through the cytoplasmic bridges.