Mammalian neo-oogenesis and expression of meiosis-specific protein SCP3 in adult human and monkey ovaries.

The concept of neo-oogenesis and follicular renewal during adulthood in mammalian females, including humans, is a novel concept with major significance for ovarian physiology and mammalian reproductive biology. Previous observations from our laboratory demonstrated that mesenchymal cells in the tunica albuginea are bipotent progenitors for both granulosa and germ cells in adult human ovaries. In the present studies, we demonstrate that the antibodies against meiotic entry synaptonemal complex protein 3 (SCP3)--a marker or meiosis, showed reactivity with segments of tunica albuginea and ovarian surface epithelium, and in oocytes of some primordial follicles in functional human and monkey ovaries.

Bone marrow derived cells and alternative pathways of oogenesis in adult rodents.

Oocyte generation in adult mouse ovaries by putative germ cells (PGCs) in bone marrow and peripheral blood has recently been proposed. It, however, remains unclear whether in laboratory rodents the PGCs reside in BM or the BM cells stimulate oogenesis from ovarian stem cells. We utilized immunoperoxidase staining to localize PGCs, oocytes, and BM derived cells in ovaries of adult (age 45-60 days) control and neonatally estrogenized rat females.