Down-regulation of p53 and ΔNp63 alleviates rps19-deficient phenotype. (A) p53 and ΔNp63 regulate each other expression. Expression of ΔNp63 is decreased in rps19-deficient embryo injected with 8 ng of p53-specific morpholinos. On the contrary, expression of p53 in RPS19-deficient embryo injected with high dose (8 ng/embryo) of ΔNp63-specific morpholino is increased. RNA was prepared from 30 embryos at each time point. (B) Coinjection of low doses of p53-specific and ΔNp63-specific morpholinos increases the number of morphologically normal embryos among morphants. Eighty embryos were injected in each group. A result representative of 3 independent experiments is shown. (C) Pharmacologic inhibition of p53 pathway by a small molecule pifithrin μ improves phenotype of rps19-deficient embryos. Eighty injected embryos were used for the control and experimental group.