Ecdysis triggering hormone signaling in arthropods.
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.
Roller
Ladislav
L
Institute of Zoology, Slovak Academy of Sciences, Dúbravská cesta 9, 84506 Bratislava, Slovakia.
Zitnanová
Inka
I
Dai
Li
L
Simo
Ladislav
L
Park
Yoonseong
Y
Satake
Honoo
H
Tanaka
Yoshiaki
Y
Adams
Michael E
ME
Zitnan
Dusan
D
D000595:Amino Acid Sequence; D000818:Animals; D001181:Arthropods / Q000378:metabolism* / Q000502:physiology; D001483:Base Sequence; D003058:Cockroaches / Q000378:metabolism / Q000502:physiology; D001517:Coleoptera / Q000378:metabolism / Q000502:physiology; D019295:Computational Biology; D006110:Grasshoppers / Q000378:metabolism / Q000502:physiology; D006927:Hymenoptera / Q000378:metabolism / Q000502:physiology; D007150:Immunohistochemistry; D007301:Insect Hormones / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D018884:Ixodes / Q000378:metabolism / Q000502:physiology; D008969:Molecular Sequence Data; D018978:Molting / Q000187:drug effects / Q000502:physiology*; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D010802:Phylogeny; D018000:Receptors, Peptide / Q000378:metabolism; D048494:Rhipicephalus / Q000378:metabolism / Q000502:physiology; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013712:Tenebrio / Q000378:metabolism / Q000502:physiology
D007301:Insect Hormones; D010455:Peptides; D018000:Receptors, Peptide