Figure 1.

Modes of transdifferentiation. Transdifferentiation can occur via different mechanisms: (A) Transdifferentiation may involve cell division and dedifferentiation prior to the adoption of a different phenotype (e.g., conversion of pigmented epithelial cells of the dorsal iris to lens fibres). The resulting intermediate cell type does not possess the phenotype of either the ancestor or the descendant cell type (B) Alternatively, transdifferentiation can occur through the direct conversion of one cell type to another without the requirement for cell division (e.g., conversion of pancreatic AR42J-B13 cells to hepatocytes).