Ovarian germline stem cells

Abstract

It has long been established that germline stem cells (GSCs) are responsible for lifelong gametogenesis in males, and some female invertebrates (for example, Drosophila) and lower vertebrates (for example, teleost fish and some prosimians) also appear to rely on GSCs to replenish their oocyte reserve in adulthood. However, the presence of such cells in the majority of female mammals is controversial, and the idea of a fixed ovarian reserve determined at birth is the prevailing belief among reproductive biologists. However, accumulating evidence demonstrates the isolation and culture of putative GSCs from the ovaries of adult mice and humans. Live offspring have been reportedly produced from the culture of adult mouse GSCs, and human GSCs formed primordial follicles using a mouse xenograft model. If GSCs were present in adult female ovaries, it could be postulated that the occurrence of menopause is not due to the exhaustion of a fixed supply of oocytes but instead is a result of GSC and somatic cell aging. Alternatively, they may be benign under normal physiological conditions. If their existence were confirmed, female GSCs could have many potential applications in both basic science and clinical therapies. GSCs not only may provide a valuable model for germ cell development and maturation but may have a role in the field of fertility preservation, with women potentially being able to store GSCs or GSC-derived oocytes from their own ovaries prior to infertility-inducing treatments. Essential future work in this field will include further independent corroboration of the existence of GSCs in female mammals and the demonstration of the production of mature competent oocytes from GSCs cultured entirely in vitro.

The Hippo Signaling Pathway Regulates Ovarian Function via the Proliferation of Ovarian Germline Stem Cells

“…Compared to many ovarian cell types, there are relatively few OGSCs in ovaries and there are no specific surface markers for these cells [31, 32]. Thus, the limiting factor for the study of OGSCs behavior and characteristics in vitro has been the separation and purification of these cells while maintaining their self-renewal and self-differentiation ability.…”

Differentiation of Mouse Primordial Germ Cells into Functional Oocytes In Vitro

“…Johnson et al indicated that faster depletion of oocytes in the ovaries would be caused by a higher number of atretic follicles and ovulated oocytes if neo-oogenesis does not progress to adulthood 40. An increasing number of reports has supported the existence of OSCs in the adult ovaries of mice, rats, bovines, and humans 20,30,40,46,74. In these reports, OSCs are collected from adult ovaries by live-cell sorting using fluorescent- or magnetic-activated cell sorting (FACS or MACS) with germ cell or stem cell markers, such as MVH (known as Ddx4) 102.…”

Bovine ovarian stem cells differentiate into germ cells and oocyte‐like structures after culture in vitro

“…In the last years, researches have provided evidences for the existence of female germ line cells in the ovaries of mice (Johnson et al., ; Kerr et al., ; Pacchiarotti et al., ; Sriraman, Bhartiya, Anand, & Bhutda, ; Zhang et al., ; Zou et al., ) as well as in other species, including human (Bukovsky, Svetlikova, & Caudle, ; Parte et al., ; White et al., ) and bovine (Dunplop, Telfer, & Anderson, ). Post‐natal oogenesis was also reported in mice (Garg & Sinclair, ; Johnson et al., ; Pan et al., ; Virant, ).…”