Efficiency of Neural Differentiation of Mouse P19 Embryonal Carcinoma Cells is Dependent on the Seeding Density

Serum-free culture conditions for retinoic acid-induced neural differentiation of mouse P19 embryonal carcinoma cells were determined for future ex vivo retroviral gene transfer and brain transplantation studies. Neural differentiation of P19 cells was dependent on the seeding densities, and both neurons and astroglia differentiated efficiently at high seeding densities (2 × 10⁴ and 5 × 10⁴ cells/cm²) but not at low seeding density (1 × 10⁴ cells/cm²). In addition, P19 cells cultured at 5 × 10⁴ cells/cm² showed neural differentiation whether or not they were infected with Friend leukemia virus FrC6-V, which inhibited neural differentiation at 2 × 10⁴ cells/cm². These results indicate that FrC6-V-infected P19 embryonal carcinoma cells should be seeded at high density to achieve efficient neural differentiation in vitro for ex vivo gene transfer with a FrC6-V–derived retroviral vector system.