Fig. 4. Expression of genes encoding antimicrobial peptide is not affected in TM9SF4 flies. (A,C) Expression of Attacin (Att), Diptericin (Dipt), Drosocin (Dro) and Drosomycin (Drs) as indicated, and of Actin (Act) which served as a loading control, was detected by northern blot. Expression of Diptericin, Drosomycin and Defensin (Def) by quantitative real-time PCR (B,D,E) was performed with total RNA isolated from 5- to 7-day-old flies. Control (w¹¹¹⁸, Rev45) or mutant [TM9SF4, TM9SF4/Df(2L)b82a2, TAK1²] flies were sacrificed before infection (NI) or at several time points (in hours) following infection. (A) Northern analysis of antimicrobial gene expression in E. cloacae-infected flies. Expression level of all antimicrobial encoding is similar in TM9SF4 mutants compared with Rev45 flies. Note that, because of different genetic background, w¹¹¹⁸ flies expressed slightly higher levels of antimicrobial peptides transcripts than Rev45 flies, although both strains displayed similar resistance to infection. (B) Quantitative analysis of Diptericin expression level in either E. cloacae- or K. pneumoniae-infected TM9SF4 mutant and Rev45 control flies. (C) Northern analysis of Drosomycin expression in Enterococcus faecalis TM9SF4 mutant and w¹¹¹⁸ (w) control infected flies. (D) Quantitative analysis of the expression level of Drosomycin in Micrococcus luteus-infected flies. (E) Quantitative analysis of Defensin expression in Rev45 and TM9SF4/Df(2L)b82a2 transheterozygous flies (TM9SF4/Df). These flies are deficient for TM9SF4 and hemizygous for the Defensin locus. In B,D and E, results are expressed as the fold induction compared with non-infected flies. Post-infection times in hours are indicated below each histogram.