Ecdysis Triggering Hormone Signaling in Arthropods

Peptides. 2010 Mar;31(3):429-41. doi: 10.1016/j.peptides.2009.11.022. Epub 2009 Nov 29.

Abstract

Ecdysis triggering hormones (ETHs) from endocrine Inka cells initiate the ecdysis sequence through action on central neurons expressing ETH receptors (ETHR) in model moth and dipteran species. We used various biochemical, molecular and BLAST search techniques to detect these signaling molecules in representatives of diverse arthropods. Using peptide isolation from tracheal extracts, cDNA cloning or homology searches, we identified ETHs in a variety of hemimetabolous and holometabolous insects. Most insects produce two related ETHs, but only a single active peptide was isolated from the cricket and one peptide is encoded by the eth gene of the honeybee, parasitic wasp and aphid. Immunohistochemical staining with antiserum to Manduca PETH revealed Inka cells on tracheal surface of diverse insects. In spite of conserved ETH sequences, comparison of natural and the ETH-induced ecdysis sequence in the honeybee and beetle revealed considerable species-specific differences in pre-ecdysis and ecdysis behaviors. DNA sequences coding for putative ETHR were deduced from available genomes of several hemimetabolous and holometabolous insects. In all insects examined, the ethr gene encodes two subtypes of the receptor (ETHR-A and ETHR-B). Phylogenetic analysis showed that these receptors fall into a family of closely related GPCRs. We report for the first time the presence of putative ETHs and ETHRs in genomes of other arthropods, including the tick (Arachnida) and water flea (Crustacea). The possible source of ETH in ticks was detected in paired cells located in all pedal segments. Our results provide further evidence of structural and functional conservation of ETH-ETHR signaling.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Arthropods / metabolism*
  • Arthropods / physiology
  • Base Sequence
  • Cockroaches / metabolism
  • Cockroaches / physiology
  • Coleoptera / metabolism
  • Coleoptera / physiology
  • Computational Biology
  • Grasshoppers / metabolism
  • Grasshoppers / physiology
  • Hymenoptera / metabolism
  • Hymenoptera / physiology
  • Immunohistochemistry
  • Insect Hormones / chemical synthesis
  • Insect Hormones / chemistry
  • Insect Hormones / metabolism*
  • Insect Hormones / pharmacology*
  • Ixodes / metabolism
  • Ixodes / physiology
  • Molecular Sequence Data
  • Molting / drug effects
  • Molting / physiology*
  • Peptides / chemical synthesis
  • Peptides / chemistry
  • Peptides / metabolism*
  • Peptides / pharmacology*
  • Phylogeny
  • Receptors, Peptide / metabolism
  • Rhipicephalus / metabolism
  • Rhipicephalus / physiology
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Tenebrio / metabolism
  • Tenebrio / physiology

Substances

  • Insect Hormones
  • Peptides
  • Receptors, Peptide

Associated data

  • GENBANK/AB469047