Induction Of Spermatogenesis And Sperm Maturation Of Testis In Young Cynomolgus Monkeys

Spermatogenesis begins with differentiation of spermatogenic cells and terminates in the formation of mature sperm.Spermatogenesis is controlled by multiple genes,which is regulated by the hypothalamic pituitary testicular axis.Is also depends on the integrity of the structure and function of spermatogenic tissue,affected by a variety of cytokines,involving cell proliferation,division,and cell differentiation and a series of complex dynamic processes.In recent years,great efforts have been made to recapitulate spermatogenesis.These efforts have identified more than 3,000 genes which are involved in spermatogenesis.So the complexity of this physiological process can be seen,but it is still not sufficient.Therefore,much remains to be understood thoroughly.The purpose of this thesis is based on control of hypothalamic-pituitary-testicular gonadal axis to testicular development,as theory.Using reproductive hormone induced testis tissues developing and spermatogenesis to obtain sperm from juvenile monkeys and breed their offspring,which shortens the period of primate animal generation and accelerates breed,not only for the research of sperm maturation establishing the model,also providing ideas for the rapid propagation of transgenic monkeys.Thus,the thesis aim to using testicular xenotransplantation,testicular tissue culture in vitro and induced precocious puberty model for studying testicular and sperm development,in order to collect mature spermatozoa and generating offspring with assisted reproductive techniques.Experiment I: The testis tissues of 3-month-old baby monkeys were selected for xenotransplantation.Xenografts of testis tissue were transplanted subcutaneously into 19 nude mice.The mice were randomly divided into two groups: FSH group(daily injection of FSH 1 IU)and the control group.FSH group showed significantly thickening of seminiferous tube compared with the control group.After 11 month,suspected sperm cellsappeared in the seminiferous tube of xenografts.Experiment II: The testis tissues of 3-month-old baby monkeys were selected for culturing in vitro.Tissue culturing were randomly divided into three groups: FSH group(5IU/mL FSH in culture medium),testosterone group(50 ng/m L testosterone in culture medium)and control group(no exogenous hormones added).The results showed that the diameters of seminiferous tubules in FSH and testosterone groups were greater than that in control group.After 4 months of culturing,suspected sperm cells were observed.Experiment III: two monkeys in age of 1.9 to 2 years old were employed.We injected GnRH 60?g/day for each.We dissolved GnRH 60?g in physiological saline,equally divided them into six parts and we injected to each monkeys intramuscularly in every 3hours.Four months later,mature sperm were collected through electrical stimulation method.These spermatozoa were injected into mature oocytes to form embryos and developed into blastocysts.Here,for the first time,we successfully induced juvenile cynomolgus monkeys precocious puberty.Supplements of FSH and testosterone could improve the development of seminiferous tube of testis of baby monkeys.