Low-expressed testis-specific calcium-binding protein CBP86-IV (CABYR) is observed in idiopathic asthenozoospermia

To investigate the expression level of testis-specific calcium-binding protein CBP86-IV in normal and asthenozoospermic human sperm. The total RNA was extracted from human sperm, and target cDNA was obtained by reverse transcription–polymerase chain reaction. Then the cDNA was used for quantitative PCR analysis and cloned into the prokaryotic expression vector pET-28a, respectively. The fusion protein was induced and expressed as inclusion body which was used to produce the polyclonal antibody against TSCBP86-IV. The protein expression level of TSCBP86-IV from normal human sperm and idiopathic asthenozoospermic samples was detected by the purified antibody. The experimental results showed that the protein expression of TSCBP86-IV was reduced in idiopathic asthenozoospermia and consistent with the transcriptional changing tendency which was detected by quantitative PCR analysis. The stable and reliable change of TSCBP86-IV may be taken as a new molecular marker for clinical diagnosis of idiopathic asthenozoospermia.