Unusual complement of three AKH octapeptides in two species of grasshoppers (Caelifera)

Abstract

Abstract. The corpora cardiaca (CC) of the two grasshopper species Zonocerus elegans (Pyrgomorphidae) and Lamarckiana sparrmani (Pamphagidae) contain (a) substance(s) that cause(s) hyperlipaemia in the migratory locust and hypertrehalosaemia in the American cockroach. Isolation of neuropeptides belonging to the adipokinetic hormone (AKH) family was achieved by single-step reversed-phase high performance liquid chromatography of CC extracts from both species and monitoring tryptophan fluorescence. The material of both species showed three distinct fluorescence peaks with adipokinetic activity in the migratory locust. The peptides were identifid by at least two of the following methods: (1) sequencing by Edman degradation, (2) sequencing by tandem fast atom bombardment mass spectrometry, (3) mass determination by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry and (4) co-elution of the native and synthetic peptides. Both species were found to have three AKH peptides stored in the CC, but unlike in other grasshoppers, none of those peptides were decapeptides. In Z. elegans the following three octapeptides occur: Schgr-AKH-II (pELNFSTGWamide), Peram-CAH-II (pELTFTPNWamide) and Phymo-AKH-III (pEINFTPWWamide), whereas L. sparrmani contains the octapeptides Grybi-AKH (pEVNFSTGWamide), Pyrap-AKH (pELNFTPNWamide) and also Phymo-AKH-III. Conspecific bioassays show no adipokinetic and only a weak (not significant) hypertrehalosaemic effect (in the pamphagid grasshopper). Some explanations are offered on the possible role of these peptides in the species investigated by interpreting their life style.

Comparative analysis of adipokinetic hormones and their receptors in Blattodea reveals novel patterns of gene evolution

“…We also confirm the presence of Manto‐CC in termites, being previously only recorded from the order Mantophasmatodea (Gäde et al, 2005) and also recently verified by mass spectrometry in the termite K. flavicollis (Marco et al, 2022). Another surprising discovery from the current work is that Pyrap‐AKH is also present in cockroaches, where previously it had been found in Hemiptera (Kodrík et al, 2000; Gäde and Marco, 2022), Orthoptera (Caelifera) (Gäde, 2006) and in some beetle species (Gäde et al, 2019).…”

“…Multiple AKHs have been reported in other insects, such as one decapeptide and two octapeptides in the migratory locust, Locusta migratoria (Oudejans et al, 1991; Siegert et al, 1985; Stone et al, 1976). One octapeptide and two decapeptides are also described from the African froghopper, Ptyelus flavescens (Gäde et al, 2017), while certain grasshoppers have three octapeptides (Gäde, 2006) and even five mature peptides (octa‐, nona‐ and decapeptides) have been isolated and sequenced from two species of the lepidopteran genus Hippotion (Gäde et al, 2013). We also confirm the presence of Manto‐CC in termites, being previously only recorded from the order Mantophasmatodea (Gäde et al, 2005) and also recently verified by mass spectrometry in the termite K. flavicollis (Marco et al, 2022).…”

Primary structure of an adipokinetic neuropeptide from the Rhinoceros Beetle, Oryctes rhinoceros L (Coleoptera: Dynastidae)

“…There are at least two aromatic acids, at position 4 mostly phenylalanine (but sometimes tyrosine) and at position 8 tryptophan, and a few peptides have a third aromatic amino acid either at position 2 (Tyr or Phe) or at position-7. 3,4 It acts on the fat body to mobilize stored lipids and carbohydrates, activate glycogen phosphorylase, accumulate cAMP 5,6,7 and inhibit the synthesis of lipids 8,9 proteins 10,11 and RNA. 12 …”