Objective  To evaluate the odontogenetic ability of first branchial arch cells of E12.5 rats.   Methods  First branchial arch cells (mandibular process) of E12.5 SD rats were isolated enzymatically and collected. After combined with gelatin sponge

the cells were transplanted into the renal capsule of a rat. The specimen was taken out and evaluated by histological and immunohistochemical methods in 4 weeks after growth in renal capsule.   Results   The first branchial arch cells with gelatin sponge developed dentin-pulp complex-like structure. Dentin sialoprotein (DSP) was expressed in the newly formed dentin-like structure. The green mineralized matrix was further identified with Masson’s trichrome staining.   Conclusion  Cells from first branchial arch of E12.5 rats can partially keep genetic signal of tooth growth and form dentin-pulp complexlike structure in renal capsule.