Mechanism of mammalian germ cell development: toward assisted new reproductive technologies.

Approximately 10% of Japanese couples who want to have children experience infertility, and the majority of these individuals have either abnormal egg cell or abnormal sperm development. In addition, currently, there is a low birth rate in many parts of the developed world; therefore, it is critical to elucidate the mechanisms of germ cell development. Thus, the study of assisted reproductive technologies has scientific significance, and is a key to solving infertility problems. This review summarizes the development of mouse germ cells, particularly focusing on the role of Nanos genes, which are essential for the development of mouse germ cells and have been identified as genes that are involved in human infertility. We also briefly introduce a study in which this information is applied to assisted reproductive technologies.