Proteomic Characteristics Of Human Sperm Cryopreservation And A Study On A Differentially Expressed Protein FAM-110A

It is estimated that 10%-20% of couples in worldwide are diagnosed with infertility, among which half of them are male infertility. With the development of economy, the sperm quality has been declined because of the increasing harmful environmental factors and unhealthy habits. Human sperm bank is a department which aims to cure the infertility and prevent the genetic diseases, and collect, test, provide sperm by ultralow cryopreservation. The human sperm bank has provided the patients of azoospermatism and oligoasthenoterazoospermia with option. However, the motility, viability, capacitation and reactive action will damage. It is believed that the changes in osmotic pressure is the main reason of damage in ultra-structure, however, the changes in ultra-structure can not explain the function loss. As the proteins are the important executor on behalf of cell function. Knowing the protein changes after thawing plays a very important role in understanding the mechanism of human sperm cryoinjury.To better understand the molecular mechanisms involved in sperm cryoinjury, 2-D PAGE and MALDI-TOF technologies were used to establish a comparative proteomie profile of the sperm between fresh and thawed sperm. A toal of 27 proteins were identified, which could contribute to understand the mechanism of human sperm cryoinjury and provide with evidence for improvement of cryoprotectants.To investigate the correlation between interested proteins and sperm functions after thawed, we chose a differentially expressed protein(protein FAM-110A). Here we have identified a novel gene Fam-110a(Family with sequence similarity 110, member A), which was conserved in mammalian species. FAM-110 A was predominantly expressed in the postpartum and adult mouse testes at mRNA and protein levels. Its expression was increased during the first wave of the spermatogenesis, indicating that FAM-110 A may be associated with the meiotic process. Further immunofluorescence staining showed that higher expression was observed in round and elongating spermatids where FAM-110 A was localized to the acrosome of round and elongating spermatids. In addition, to assess if FAM-110 A was involved in fertilization, in vitro fertilization assays in the presence of anti-FAM-110 A antibody was performed. Anti-FAM-110 A antibody was found to remarkably inhibited fertilization in mice.To sum up, through a series of research of protein FAM-110 A, we first clarify the position and function of a testis specific gene and put forward the following views: protein FAM-110 A as the acrosin participates in the occurrence and the fertilization process of sperm. This might be involved in the decline of motility, viability, intact acrosome and concentration of calcium in thawing sperm, which could contribute to understand the mechanism of human sperm cryoinjury and provide with evidence for improvement of cryoprotectants.