Infection and ectopic activation of the IMD-pathway induces expression of antimicrobial peptides in the salivary glands. Oral infection of early 3rd instar with the insect pathogen Erwinia carotovora was used to monitor transcriptional changes in 3 selected antimicrobial peptide genes, drosomycin (drs), cecropin (cec) and diptericin (dipt)(white bars). Ectopic overexpression of the prgp-lc gene in the larval salivary glands was achieved using the Gal4/UAS system (sgs3::gal4 X UAS::pgrp-lc). Salivary glands of early 3rd instar larvae were isolated from these crossing and a parental line (responder line) used for control. Quantitative real-time PCR was performed with oligonucleotides comprising approximately 150 bp of the corresponding antimicrobial peptide genes; drosomycin (drs), cecropin (cec), diptericin (dipt), metchnikowin (metch), drosomycin (dros) and defensin (def) (grey bars). Results are the mean of at least 3 experiments performed in triplicate. Controls are set to 1. Statistically significant differences (compared with controls are marked by an asterik (p < 0.05).