Fig. 1.

Histology of differentiated elements found in teratomas formed after E21 and E24 pig embryonic liver-precursor transplantations. Teratoma-like structures in liver implants of E21 and E24 are characterized by a mixed growth of various embryonic tissue types. (a) Cartilage stained by Alcian blue and hepatocytes stained by PAS (purple). (b) Columnar epithelia lining cystic structures are decorated by cytokeratine MNF116. (c) Striated-muscle fibers stained by sarcomeric actin. (d) Bone fragment (osteoclast cell is indicated with an arrow, and osteoblasts are indicated with arrowheads) with H&E staining.