Figure 8

Model of ovarian cords and mesenchymal compartment organization in fetal ovaries during gonadogenesis up to early folliculogenesis. In female gonads, a specific organization in ovarian cords appear. The majority of germ cells in the first trimester ovary are early germ cells, but in the second trimester both early and more mature germ cells (morphological bigger germ cells) were present and segregated spatially in the ovary: early germ cells located closer to the surface whereas the more mature (bigger) germ cells are located in the inner part of the cortex [17]. From W17, individual primordial follicles become embedded in the mesenchymal compartment and at birth all germ cells are present as individual primordial follicles in the mesenchymal compartment which supports the further development of these follicles up to ovulation in adulthood.