Figure 2.

Morphology and biological markers expression by rat BMSCs cultured on the lower layer of the transwell co-culture system in conditioned media. (A) Morphology of BMSCs in co-culture system showed small round cells, and double round cells with intercellular bridges. Allied cells were observed. (a,b) Cells became smaller and rounder in shape; (c) right lower insert: double-round-cells, with intercellular bridge; (d) right upper insert: allied cells; arrow: the presumed dynamic morphology changes (bar: 100 μm); (B) Transmission electron microscope examination showed that BMSCs in the co-culture system exhibited large round nuclei, obvious chromatospherites, more heterochromatin in the nucleus, and more mitochondria in intracytoplasm (×8000); (C) Expression of spermatogonial specific protein in each group of cells detected by Western blot: induced BMSCs expressed integrin-β, which was not expressed in BMSCs, expressed higher levels of c-kit and GCNF than that in non-induced BMSCs.