ABSTRACT
SOURCE OF ARTIFICIAL OOCYTES A major requirement of any cell type used to form arti- cial gametes would be that they can be collected from adult tissue, as this eliminates the use of primordial germ cells, which are only present during fetal life (1). Research has focused on obtaining articial oocytes from three main cell types: ESCs, induced pluripotent stem cells (iPSCs) and oogonial stem cells (OSCs) or germline stem cells (GSCs). Stem cells are undierentiated or dierentiationlimited, self-renewing cells within a distinct niche responsible for renewal. Pluripotent stem cells have the ability to dierentiate into all the cells of a mammalian embryo and therefore harbor the potential to generate germ cells. Mammalian oogenesis in vivo is a tightly coordinated process that requires the transient switching on and o of regulatory genes and molecular processes, of which we still have limited knowledge (Figure 30.1).
