Expression of CatSper family transcripts in the mouse testis during post-natal development and human ejaculated spermatozoa: relationship to sperm motility

摘要

CatSper is a unique sperm cation channel-like protein family exclusively expressed in the testis and plays important roles in sperm functions. The temporal expression profiles of CatSper1–4 mRNAs in the mouse testis during post-natal development through adulthood were investigated using real-time RT–PCR. The CatSper2 transcript was present in the testis of the 8-day-old mice, and was repressed in the adult testis after two sharp up-regulations at day 18 and 35. CatSper1 and CatSper3, 4 mRNAs were detectable in the testis of 18-day and 15-day-old mice, respectively. After sharp up-regulation at day 25 and 35, respectively, they were maximal at the adult testis stage. The differences between the temporal expression profiles of the CatSper transcripts in post-natal mouse testis development suggest different regulation to their transcription, and potentially contribute to the possibility of forming heteromeric channels among these four CatSper family members. CatSper1–3 transcripts were identified to be present in the human ejaculated spermatozoa by RT–PCR. Significantly higher levels of CatSper2 and CatSper3 mRNAs revealed by real-time RT–PCR were observed in the high-motile spermatozoa than in the low-motile fraction and suggests that CatSper2 and CatSper3 transcripts in the human ejaculated spermatozoa could be the potential targets for further study and male infertility screening.