Fig. 5

In vitro culture of manually scraped sheep ovary surface epithelial (OSE) cells in presence of FSH. a-b OSE cells in initial culture show presence of different cell types including large epithelial cells (white arrow), small spherical VSELs and slightly larger OSCs (yellow arrow). Stem cells are observed in close association with large epithelial cells. c-d Untreated (without FSH) OSE cells after 24 h of culture show minimal effect on stem cells e-g FSH treatment for 24 h resulted in distinct changes in OSE culture. Spherical stem cells appeared to increase in numbers and formed small spheres in close association with epithelial cells bed. f Epithelial cells became flat and were attached to bottom of the culture dish. g Cluster of stem cells formed by incomplete cytokinesis (clonal expansion) resembled germ cell nest-like structures