摘要
Spermatogenesis is a complex, unique process that takes place in the testis. It consists of a set of events including mitotic （from spermatogonia to primary spermatocytes） and meiotic divisions （from primary spermatocytes to early round spermatids）, and spermiogenesis, a differentiation step from early round spermatids to testicular spermatozoa Although spermatogenesis is known as a well autocrine- and paracrine-regulated process, some proteins involved in its regulation remain to be determined. Related to this, the recent study conducted by Dai et al. have shed light on the relevant function of SET protein, a protein phosphatase 2A （PP2A） inhibitor, also known as I2PP2A, or TAF-Ib. This protein, identified for the first time in 1992, has been described to be involved in multiple cell functions, such as control of cell cycle and apoptosis, gene transcription, epigenetic regulation, and nucleosome assembly. Apart from these functions, it is worth noting that SET has been to be involved in the regulation found in theca cells, where appears of androgen biosynthesis, and in mature oocytes, where plays a key role in the segregation of sister chromatids during the second meiotic division SET protein inhibits PP2A by enhancing lyase activity of P450c17, a substrate for PP2A when it is Serand Thr-phosphorylated. PP2A function in reproductive physiology is not restricted to gamete production （i.e. spermatogenesis and oogenesis）, but this protein is also involved in human sperm capacitation.
Spermatogenesis is a complex, unique process that takes place in the testis. It consists of a set of events including mitotic （from spermatogonia to primary spermatocytes） and meiotic divisions （from primary spermatocytes to early round spermatids）, and spermiogenesis, a differentiation step from early round spermatids to testicular spermatozoa Although spermatogenesis is known as a well autocrine- and paracrine-regulated process, some proteins involved in its regulation remain to be determined. Related to this, the recent study conducted by Dai et al. have shed light on the relevant function of SET protein, a protein phosphatase 2A （PP2A） inhibitor, also known as I2PP2A, or TAF-Ib. This protein, identified for the first time in 1992, has been described to be involved in multiple cell functions, such as control of cell cycle and apoptosis, gene transcription, epigenetic regulation, and nucleosome assembly. Apart from these functions, it is worth noting that SET has been to be involved in the regulation found in theca cells, where appears of androgen biosynthesis, and in mature oocytes, where plays a key role in the segregation of sister chromatids during the second meiotic division SET protein inhibits PP2A by enhancing lyase activity of P450c17, a substrate for PP2A when it is Serand Thr-phosphorylated. PP2A function in reproductive physiology is not restricted to gamete production （i.e. spermatogenesis and oogenesis）, but this protein is also involved in human sperm capacitation.
