Expression of Atg8b-GFP with Dcp-1 in S2 cells. S2 cells were transfected with Atg8b-GFP with or without Dcp-1 constructs were maintained under (A) FBS supplied or (B) starvation-inducing culture conditions. (C) Atg8b-GFP was induced with full-length (fl-) Dcp-1 in the presence of FBS. (D) Atg8b-GFP was induced with truncated (t-) Dcp-1. (E) The percentage of cells with multi-autophagosomes was counted by cell number of punctate Atg8b-GFP expression. (n of; control: 1,705, 2 hour starvation: 1,353, 4 hour starvation: 1,464, 6 hour starvation: 1,304, t-Dcp-1: 1,019, fl-Dcp-1:1,031, (*, P < 0.05; **, P < 0.01 t test). Starvation is abbreviated to ST. Scale bars in A-D stand for 10 um. We also tested the expression level of Dcp-1 and Atg8b in the lines that over-express Dcp-1 with Atg1, Atg6, Aut1 and S 6kwtbut we found that the gene expression levels were not significantly affected in any case (Additional file 7).