CCHamide-2 Signaling Regulates Food Intake and Metabolism in Gryllus bimaculatus

Abstract

Neuropeptides play vital roles in energy homeostasis in insects and other animals. Although the importance of the regulatory network of neuropeptides in feeding and metabolism has been illuminated, a complete understanding of the mechanisms has not been addressed as many factors are involved in the regulation. CCHamide-2 is a newly identified brain-gut neuropeptide that regulates feeding behavior in several insect species including Drosophila melanogaster. However, little is known about the mechanisms controlling the feeding-related behavior and metabolic functions modulated by CCHamide-2 in other insects. In this study, we addressed the functions of CCHamide-2 in the two-spotted cricket, Gryllus bimaculatus, which was used as the experimental material to research the mechanisms of feeding and metabolism in this omnivorous insect species. Knockdown crickets by RNA interference against GbCCHamide-2R increased the amount of food intake, while injection of chemically synthetic GbCCHamide-2 peptide reduced the amount of food intake. Further, knockdown and peptide injection experiments revealed that GbCCHamide-2 signaling increased the concentrations of circulating lipids and carbohydrates, and the carbohydrate-rich diet increased the transcript levels of GbCCHa-2R. Moreover, GbCCHa-2 injection decreased the transcript level of Gbilp. By contrast, GbCCHamide-2 signaling did not affect nymphal growth or the transcript level of GbAKH, as well as feeding preferences. Taken together, CCHamide-2 signaling in G. bimaculatus regulates food intake associated with alterations in lipid and carbohydrate levels in hemolymph.

Comparative study of neuropeptide signaling systems in Hemiptera

“…, 2015) and Gryllus bimaculatus (Zhu et al. , 2022). LK encodes a neuropeptide that also regulates food intake and water balance (Al‐Anzi et al.…”

“…However, these neuropeptides were found in closely related species. CCHa2 was initially discovered in B. mori (Roller et al, 2008), and it regulates the food intake in D. melanogaster (Ren et al, 2015) and Gryllus bimaculatus (Zhu et al, 2022). LK encodes a neuropeptide that also regulates food intake and water balance (Al-Anzi et al, 2010).…”

Functional characterization of CCHamides and deorphanization of their receptors in the yellow fever mosquito,Aedes aegypti

“…In the pea aphid, Acyrthosiphon pisum , the expression of the presumed CCHa2 receptor was found to be significantly increased in starved aphids while knockdown by RNAi led to a reduction in food intake and reproductive output but had no influence on survival (Shahid et al, 2021). Recent work in the two-spotted cricket, Gryllus bimaculatus , revealed that synthetic CCHa2 (GbCCHa-2) injection reduced food intake (as determined by the number of fecal pellets excreted) and increased carbohydrate and lipid levels in the haemolymph while knockdown of its receptor (GbCCHa-2R) increased food intake and led to a corresponding reduction in haemolymph lipid levels (Zhu et al, 2022).…”

Best Practices for Comprehensive Annotation of Neuropeptides of Gryllus bimaculatus

“…Comparative studies with other insect neuropeptide sequences were performed by searching the transcriptome sequences assembled from RNA-seq [ 5 , 6 , 7 , 8 ] to identify neuropeptides in the two-spotted cricket, Gryllus bimaculatus . Although analysis through de novo transcriptome assembly reveals the high coverage of transcripts, information on genomic loci was not available.…”