Venom Peptide Repertoire of the European Myrmicine Ant : Identification of Insecticidal Toxins.

Using an integrated transcriptomic and proteomic approach, we characterized the venom peptidome of the European red ant, . We identified 13 "myrmicitoxins" that share sequence similarities with previously identified ant venom peptides, one of them being identified as an EGF-like toxin likely resulting from a threonine residue modified by fucosylation. Furthermore, we conducted insecticidal assays of reversed-phase HPLC venom fractions on the blowfly , permitting us to identify six myrmicitoxins (i.e., U-, U-, U-, U-MYRTX-Mri1a, U-MYRTX-Mri1b, and U-MYRTX-Mri1c) with an insecticidal activity. Chemically synthesized U-MYRTX-Mri1a, -Mri1b, -Mri1c, and U-MYRTX-Mri1a irreversibly paralyzed blowflies at the highest doses tested (30-125 nmol·g). U-MYRTX-Mri1a, the most potent neurotoxic peptide at 1 h, had reversible effects after 24 h (150 nmol·g). Finally, U-MYRTX-Mri1a has no insecticidal activity, even at up to 55 nmol·g. Thus, employs a paralytic venom rich in linear insecticidal peptides, which likely act by disrupting cell membranes.