02597nas a2200289   4500008004600000245018300046210006900229300001400298490000700312520151200319653001201831653002501843653004301868653001601911653003801927653003201965653004101997653005502038653004502093653003402138100001602172700001702188700001402205700001802219700002002237856005002257       Submitted                   eng d     00aComparison of the effects of pyrokinins and related peptides identified from arthropods on pupariation behaviour in flesh fly (Sarcophaga bullata) larvae (Diptera: Sarcophagidae)0 aComparison of the effects of pyrokinins and related peptides ide  a233 - 2390 v503 aPeptides from the pyrokinin/PBAN family and some structurally related compounds identified in various arthropods were tested for acceleration of puparial contraction in flesh fly larvae. Modifications of behavioural patterns of pupariation were further studied for the active compounds using a behavioural analysis based on the recording of changes in tension of the cuticle. Nine peptides belonging to the pyrokinin/PBAN family (Lem-PK, Pea-PK-5, Lom-PK II, Hez-PBAN, Bom-DH-I), identified in five different insect species, two pyrokinin peptides derived from the genome of Drosophila melanogaster (capa-3, and hugin), and two pyrokinins identified from the white shrimp Penaeus vannamei were very active in the pupariation assay, with threshold doses within the range of 0.1-5.0 pmol larva(-1). High activity was also detected for a related peptide ETH1 from Drosophila. All of these peptides share a C-terminal PRLamide, which is essential and sufficient for the activity. Interestingly, two other structurally related peptides from Drosophila--ETH2 and capa-1--which feature conservative changes (Ile and Val, respectively) at the C-terminal Leu position, were inactive within a physiological range of concentrations. It is clear that the receptor mediating the acceleration of puparial contraction behaviour is sensitive to the introduction of greater steric bulk at the C-terminal Leu position. The peptides that accelerated pupariation showed very similar patterns of muscular and cuticular activity.10aAnimals10aArthropods/chemistry10aBiological Factors/analysis/physiology10adevelopment10aDiptera/drug effects/*growth &amp10aInsect Hormones/*physiology10aInsect Proteins/analysis/*physiology10aMetamorphosis, Biological/drug effects/*physiology10aNeuropeptides/classification/*physiology10aPupa/drug effects/growth &amp1 aZd'arek, J.1 aVerleyen, P.1 aMares, M.1 aDoleckova, L.1 aNachman, R., J.  uhttps://sarcophagidae.myspecies.info/node/76502802nas a2200313   4500008004600000245017800046210006900224300001400293490000700307520167000314653001701984653002802001653001202029653001602041653002502057653003702082653003502119653002902154653003602183653004202219653003502261653003402296653003602330100001402366700001602380700002002396700002202416856005002438       Submitted                   eng d     00aDiapause hormone in the corn earworm, Helicoverpa zea: optimum temperature for activity, structure-activity relationships, and efficacy in accelerating flesh fly pupariation0 aDiapause hormone in the corn earworm Helicoverpa zea optimum tem  a196 - 2050 v293 aDiapause hormone (DH) effectively terminated pupal diapause in Helicoverpa zea. This effect was temperature-dependent, with an optimum of 21 degrees C. The dose-response curve indicated an ED50 of DH for diapause termination of approximately 100 pmol. The core sequence and essential amino acids were determined by bioassays using modified and truncated DH analogs. A C-terminal hepta-peptide, LWFGPRLa, was the core sequence required for diapause termination. Activity was lost when Alanine was substituted for any of the amino acids in the hepta-peptide, with the exception of Glycine. A fragment series of analogs suggested that the amide and Arginine were the most important components needed for terminating diapause. Leucine, Tryptophan, and Phenylalanine at the N-terminus of the hepta-peptide were also critical for activity. The C-terminal Leucine was less important: deletion resulted in decreased activity, although it could not be substituted by Alanine. The fact that a portion of the DH sequence is similar to the pyrokinin that accelerates fly pupariation prompted us to also evaluate the capability of DH to accelerate development in the flesh fly, Sarcophaga bullata. The threshold dose of DH essential to accelerate fly pupariation was 5 pmol for immobilization/retraction and longitudinal contraction and 10 pmol for tanning, approximately one or two orders of magnitude lower than the effective dose required for diapause termination in H. zea. Tensiometric measurements revealed that DH affected neuromuscular patterns of pupariation behavior and associated cuticular changes in a manner similar to that of the fly pyrokinins and their analogs.10a*Temperature10aAmino Acid Substitution10aAnimals10adevelopment10aDiptera/*growth &amp10aDose-Response Relationship, Drug10aLarva/drug effects/growth &amp10aLepidoptera/*growth &amp10aMuscle Contraction/drug effects10aNeuropeptides/chemistry/*pharmacology10aPeptide Fragments/pharmacology10aPupa/drug effects/growth &amp10aStructure-Activity Relationship1 aZhang, Q.1 aZd'arek, J.1 aNachman, R., J.1 aDenlinger, D., L.  uhttps://sarcophagidae.myspecies.info/node/363