Figure 4.

RP-HPLC of acidic extracts obtained from the hemolymph of control and 24-h bacteria-challenged Drosophila. Hemolymph of 20 control and 20 bacteria-challenged flies (BC 24 h) were diluted in 0.1% TFA and were analyzed separately on an Aquapore RP300 C₈ column (see Materials and Methods). Absorbance was monitored at 214 nm. The DIMs numbered from 1 to 19, revealed by differential MS analysis in Fig. 1, were detected by MALDI-TOF MS in the HPLC fractions of the hemolymph from bacteria-challenged flies. Four of the already characterized Drosophila antimicrobial peptides [drosocin monosaccharide (MS) and disaccharide (DS), metchnikowin, and drosomycin] are reported on the figure according to their names.