Fig. 1

Two populations of stem cells (VSELs and OGSCs) in adult ovary. a H&E stained sheep OSE smear. Two distinct populations of stem cells including VSELs (arrow) which are smaller than the red blood cells and slightly bigger OGSCs (asterix) are clearly visualized even after gently scraping sheep ovary fixed overnight in neutral buffered formalin. Red blood cells and epithelial cells are also clearly visualized [4]. b (i-vi) Characterization of ovarian stem cells using pluripotent markers OCT-4 and SSEA-4. Smaller VSELs express nuclear OCT-4 and cell surface SSEA-4 whereas slightly bigger OGSCs express cytoplasmic OCT-4 and minimal SSEA-4. Note the VSELs do not stain with DAPI [3]. c (i) Sheep OSE smear immuno-stained with FSHR antibody. Note epithelial cells are negative whereas the stem cells exhibit distinct positive stain. (ii) Confocal microcopy localization of FSHR on VSELs, OGSCs and on a germ cell nest. (iii-iv) in situ hybridization of FSHR on ovarian stem cells after FSH treatment using oligoprobes specific for FSHR1 and FSHR3 respectively. Note active transcription of FSHR3 mRNA in the cytoplasm of stem cells after FSH treatment whereas FSHR1 is expressed in the stem cells and the expression is not affected by FSH treatment. d qRT-PCR analysis of FSHR1 and FSHR3 after 3 and 15 h of FSH treatment. Note that only FSHR3 levels are increased transiently after 3 and return to basal levels by 15 h. c and d panels show earlier published data by Patel et al. [7]. Please refer to the cited references for further details