Fig. 2

FUHEN cells in culture. The frog LTBMC. Large adherent stromal cells and hematopoietic cells were observed (phase contrast, a and b). The dashed square in a is magnified in b. The LTBMC was stained with May-Grünwald Giemsa (c, d). The dashed square in c is magnified in d. Scale bar indicates 2 mm (c) or 200 µm (d). Non-adherent cells in the LTBMC were selected, and the FUHEN cell line was established. The proliferating FUHEN cells formed large clumps (e) after 2 weeks at 28 °C. The clump size was more than 200 µm. After 4 weeks at 28 °C, huge oval-shaped cells were observed. Collar structures were observed in the oval-shaped cells (f). The white triangles represent the positions of the collar structures in the cells. Scale bar indicates 200 µm (e) or 50 µm (f)