Myotropic activity and immunolocalization of selected neuropeptides of the burying beetle Nicrophorus vespilloides (Coleoptera: Silphidae)

In this study, one of the physiological activities of proctolin, myosuppressin (Nicve‐MS), myoinhibitory peptide (Trica‐MIP‐5) and the short neuropeptide F (Nicve‐sNPF) in N. vespilloides have been investigated. The tested neuropeptides were myoactive on N. vespilloides hindgut. After application of the proctolin increased hindgut contraction frequency was observed (EC50 value was 5.47 × 10−8 mol/L). The other tested neuropeptides led to inhibition of N. vespilloides hindgut contractions (Nicve‐MS: IC50 = 5.20 × 10−5 mol/L; Trica‐MIP‐5: IC50 = 5.95 × 10−6 mol/L; Nicve‐sNPF: IC50 = 4.08 × 10−5 mol/L). Moreover, the tested neuropeptides were immunolocalized in the nervous system of N. vespilloides. Neurons containing sNPF and MIP in brain and ventral nerve cord (VNC) were identified. Proctolin‐immunolabeled neurons only in VNC were observed. Moreover, MIP‐immunolabeled varicosities and fibers in retrocerebral complex were observed. In addition, our results have been supplemented with alignments of amino acid sequences of these neuropeptides in beetle species. This alignment analysis clearly showed amino acid sequence similarities between neuropeptides. Moreover, this allowed to deduce amino acid sequence of N. vespilloides proctolin (RYLPTa), Nicve‐MS (QDVDHVFLRFa) and six isoforms of Nicve‐MIP (Nicve‐MIP‐1—DWNRNLHSWa; Nicve‐MIP‐2—AWQNLQGGWa; Nicve‐MIP‐3—AWQNLQGGWa; Nicve‐MIP‐4—AWKNLNNAGWa; Nicve‐MIP‐5—SEWGNFRGSW...
Source: Insect Science - Category: Biology Authors: Tags: ORIGINAL ARTICLE Source Type: research