Natural history of the female germ cell from its origin to full maturation through prenatal ovarian development

This paper contains a number of sketches concerning the main morphological ultrastructural features of the human female germ cell during the prenatal period. The morphodynamic outline of primordial germ cells has been traced, both in their extraembryonic site of origin and during their migration towards the developing ovary. After gonadal settlement, the intraovarian differentiation of the germ cells into primary oocytes through the stage of oogonia, as well as the dramatic fall in the number of germ cells before birth, is described. The presence of morphofunctionally relevant interactions between the differentiating female gamete and the surrounding somatic microenvironment has also been evaluated and discussed. (C) 1997 Elsevier Science Ireland Ltd.