Coculture of dermal cells and mESCs in embryoid bodies does not prevent differentiation. (a) Embryoid-like bodies formed after 3 days in hanging drop culture. Follicular dermal cells were stained with DiI and mESCs expressing GFP under the control of the CAGG promoter. Hanging drops containing follicular dermal cells produced EBs having several foci of aggregation, in contrast to those containing ES cells alone. (b) EBs after 9 days in suspension culture. EBs containing mESCs were much larger than those with only follicular dermal cells. (c) Differentiation markers expressed by mESCs in 3 dimensional cocultures with follicular dermal cells. Scale bars (a) = 50 μm and (b) = 100 μm.