Suppressive effects of dRYamides on feeding behavior of the blowfly, Phormia regina.

Toru Maeda,Yuki Nakamura,Mamiko Ozaki,Taishi Yoshii,Hajime Shiotani,Masaru K Hojo,Takahiro Sato,Morikatsu Yoshida,Masayasu Kojima,Mikiya Miyazato,Takanori Ida

doi:10.1186/s40851-015-0034-z

Abstract

Recently, dRYamides-1 and -2 have been identified as ligands of the neuropeptide Y-like receptor CG5811 in Drosophila melanogaster. It has also been reported in brief that injection of dRYamide-1suppresses the early feeding behavior called proboscis extension reflex (PER) in the blowfly Phormia regina. Immunohistochemical analyses by our group using anti-dRYamide-1 antiserum indicated symmetrical localization of 32 immunoreactive cells in the brain of P. regina. In order to analyze the mechanism of feeding regulation, we further investigated the effects of dRYamide-1 and -2 on intake volume, PER exhibition, and activity of the sugar receptor neuron. After injection of dRYamide-1 or -2, flies showed little change in the intake volume of sucrose solution, but a significant depression of PER to sucrose. Injection of dRYamide-1 revealed a significant decrease in the responsiveness of the sugar receptor neuron, although the injection of dRYamide-2 did not. These results suggest that the dRYamide peptides decrease feeding motivation in flies, as evaluated by PER threshold, through a mechanism that partially involves desensitization of the sugar receptor neuron.Electronic supplementary materialThe online version of this article (doi:10.1186/s40851-015-0034-z) contains supplementary material, which is available to authorized users.

Highlights

Bioactive peptides have been broadly studied in vertebrates and invertebrates [1,2,3,4]
In the control experiments using Ringer solutioninjected flies, when the intake volume was compared between 250 mM and 1 M sucrose, there was no significant difference in each case of Fig. 2a, b, c, and d (P >0.05, n = 5 or 6, Mann–Whitney U test)
Conclusions dRYamide-1 and dRYamide-2 were first reported as ligands of the neuropeptide Y-like receptor CG5811 in Drosophila melanogaster, and it has been suggested that dRYamide-1 suppressed the early feeding behavior, proboscis extension reflex (PER), in the blowfly P. regina

Summary

Introduction

Bioactive peptides have been broadly studied in vertebrates and invertebrates [1,2,3,4]. One type of Drosophila NPF consisting of 36 amino acid residues is referred to as long NPF [9, 10], whereas another type consisting of 6–11 amino acid residues is referred to as short NPF [9, 11]. Both the long and short NPFs are expressed in the brain and mid-gut of larvae and adults.

Results

Discussion

Conclusion