Knockdown of Atg5 promotes cyst formation in pkd1a-/- embryos. (A,A’) Injection of 4 ng of atg5 MO into one-cell staged embryos resulted in multiple defects, including loss of brain tissues, cardiac edema, and the body curvature (A, arrowhead). Cystic distension of the pronephric tubules (268/285) was observed in enlarged images (A’, arrow). Shown are lateral (A) and dorsal (A’) views of a day 2 embryo. (B,B’) Injection of 1 ng of atg5 MO led to body curvature (B, arrowhead) and small pronephric cysts (B’, arrow) in 19 out of 206 injected embryos. Shown is an embryo at 5 dpf. (C) Injection of 1 ng of atg5 MO increased the number of pkd1a-/- embryos with kidney cysts. MO was injected into embryos derived from heterozygous pkd1a inter-crosses. At 2 dpf, morphants displaying curly body phenotypes were discarded and normal-looking morphants were fixed in 4% formaldehyde, with the posterior tail collected for genotyping. Cyst formation was assessed by HE staining on JB-4 sections. Data are presented as means ± s.d. from three independent experiments. Ten to fifteen embryos per genotype were analysed in each experiment. *: P < 0.05.