Presence of DAZL transcript and protein in mature human spermatozoa

Objective: To identify the DAZL transcript and protein location in human spermatozoa. Design: In vitro experiment. Setting: University-based reproductive genetics laboratory. Patient(s): A fertile volunteer. Intervention(s): Reverse transcription-polymerase chain reaction (RT-PCR), Western blot, and immunostaining for DAZL. Main Outcome Measure(s): Expression of DAZL in human spermatozoa. Result(s): The DAZL-specific primers yield a 128 bp product in ejaculate. A protein of approximately 33.5 kDa was detected by Western blot analysis. Immunofluorescence staining showed strong homogeneous staining in the midpiece of spermatozoa and weak staining in the principal piece. A speckled-type distribution was found in the head region. Conclusion(s): The DAZL transcript and protein are present in human spermatozoa. The roles of DAZL protein in sperm motility and in the sperm-oocyte interaction await further investigation.