Figure 5. Ectopic expression of Ronin is tumorigenic.
(A) Immunohistochemical staining of Oct4 in teratocarcinoma sections. Tumors formed by EF1α-Ronin ES cells after injection into immunocompromised mice were much larger than those formed by R1 control cells (top) and more clusters of Oct4-positive cells were present (bottom), insert: 40x magnification of typical Oct4-positive cell cluster in EF1α-Ronin derived tumor, bar (top) = 0.5 cm, bar (bottom) = 0.1 mm (B) H&E staining of EF1α-Ronin teratocarcinoma sections. EF1α-Ronin ES cells were capable of differentiating into all three germ layers, as were their wild-type counterparts (data not shown), white arrows indicate cluster of undifferentiated cells, bar = 50 μm.