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Transplanted bone marrow cells do not provide new oocytes but rescue fertility in female mice following treatment with chemotherapeutic agents.

It is generally accepted that mammalian females are born with a finite pool of oocytes and that this is the sole source of ovules throughout the reproductive life of the adult. This dogma was shaken in 2003 when researchers showed that the oocyte stock might be renewable in adult mammals. It has been proposed that hematopoietic stem cells might be a source of new oocytes. These discoveries have puzzled many researchers and remain controversial. In our study, we attempted to determine if transplanted bone marrow cells could provide new oocytes in PU.1 mice and in severe combined immunodeficiency (SCID) mice after treatment with chemotherapeutic agents. We also examined the possibility that grafted bovine embryonic ovarian cortex might provide an environment favoring such a response. We found no evidence that transplanted bone marrow cells provide new fertilizable oocytes in PU.1 mice, in SCID mice treated with chemotherapeutic agents, or with bovine embryonic ovarian tissue grafts. However, transplanted bone marrow cells have improved the fertility of SCID mice previously treated with chemotherapeutic agents. These data suggest that bone marrow cells cannot provide new oocytes but can positively influence ovarian physiology to improve the fertility of mice previously treated with chemotherapeutic agents.