Fig. 6

Characterization of germ cell nest-like structures obtained after FSH treatment. These structures with incomplete cytokinesis were observed to be positive for (a) OCT-4 (b & d) VASA and (c) PCNA suggesting stem cells proliferation and clonal expansion in response to FSH treatment. Both small VSELs (arrow) and slightly bigger OSCs (asterix), asymmetric cell division and clonal expansion (circled) were clearly visualized. Note that the epithelial cells were distinctly negative for these markers. Similar structures have been earlier reported also with detailed characterization to show that they indeed represent incomplete cytokinesis and not cell aggregates [6, 7]. e qRT-PCR results on OSE cells showed increased expression of VSELs (Oct-4A, Sox-2, Stat-3), OSCs (Oct-4 and Vasa) and proliferation (Pcna) specific transcripts after 24 h of FSH treatment (red bars) compared to untreated controls (blue bars). Results are representative of three different experiments and error bars represent standard error f Transcript for alternately spliced FSHR isoform, Fshr3 appears to be more up-regulated after FSH treatment compared to the canonical isoform Fshr1 in agreement with earlier results [6, 12]