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Pheromone Biosynthesis (pheromone + biosynthesis)
Terms modified by Pheromone Biosynthesis Selected AbstractsBioavailability of backbone cyclic PK/PBAN neuropeptide antagonists , inhibition of sex pheromone biosynthesis elicited by the natural mechanism in Heliothis peltigera femalesFEBS JOURNAL, Issue 4 2010Aliza Hariton The bioavailability (i.e. ability to penetrate the insect cuticle, to reach the target organ and to exert bioactivity) of two backbone cyclic (BBC) pyrokinin/pheromone biosynthesis-activating neuropeptide (PK/PBAN) antagonistic peptides was tested by applying them topically to Heliothis peltigera females and monitoring the resulting inhibition of sex pheromone production elicited by the natural (endogenous) mechanism during scotophase. Peptides were applied at various time points before the onset of scotophase, in aqueous or organic solvents, and pheromone content was examined at the 5th or 6th hour of scotophase. Both peptides penetrated the cuticle very efficiently and inhibited sex pheromone biosynthesis elicited by the natural mechanism for up to 8 or 9 h after application. The degree of inhibition differed between solvents: those applied in double-distilled water (DDW) were more active than those applied in dimethylsulfoxide (inhibition by 53,73% and 15,38%, respectively, for BBC-25, and 46,67% and 36,40%, respectively for BBC-28). Peptides applied in dimethylsulfoxide and hexane exhibited slightly more persistent inhibitory activity than those applied in DDW. The solvents themselves did not affect sex pheromone production. Multiple applications (at ,2, 0, +2 and +4 h) resulted in almost complete (87%) inhibition of sex pheromone biosynthesis, compared with 52% inhibition following a single application. The present study is the first demonstration of the ability of topically applied PK/PBAN antagonists to inhibit sex pheromone biosynthesis elicited by the natural mechanism in female moths, and provides important information on the bioavailability of BBC peptides and the mechanism responsible for sex pheromone production in these insects. [source] Cloning and characterisation of a prenyltransferase from the aphid Myzus persicae with potential involvement in alarm pheromone biosynthesisINSECT MOLECULAR BIOLOGY, Issue 4 2008M. J. Lewis Abstract The majority of aphid species release an alarm pheromone with the most common component being the sesquiterpene (E)-,-farnesene, sometimes accompanied by other sesquiterpenes or monoterpenes. The genes/enzymes involved in the production of these compounds have not been identified in aphids although some components of isoprenoid biosynthesis have been identified in other insect species. Here we report the cloning, expression and characterisation of a prenyltransferase from the aphid Myzus persicae which can act as a farnesyl pyrophosphate synthase or a geranyl pyrophosphate synthase to produce both sesquiterpenes and monoterpenes and hence could be responsible for the biosynthesis of the observed components of the alarm pheromones. In addition, the enzyme can utilise geranyl pyrophosphate to produce farnesyl pyrophosphate showing that the synthesis of the latter involves the sequential condensation of isoprenyl pyrophosphate units. [source] Spatial distribution and differential expression of the PBAN receptor in tissues of adult Helicoverpa spp. (Lepidoptera: Noctuidae)INSECT MOLECULAR BIOLOGY, Issue 3 2007A. Rafaeli Abstract Pheromone-biosynthesis-activating neuropeptide (PBAN) regulates sex pheromone production in many female moths. PBAN-like peptides, with common FXPRLamide C-terminals are found in other insect groups where they have other functions. The ubiquity and multifunctional nature of the pyrokinin/PBAN family of peptides suggests that the PBAN receptor proteins could also be present in a variety of insect tissues with alternative functions from that of sex pheromone biosynthesis. Previously we showed the presence of the PBAN-R in Helicoverpa armigera at the protein level. In the present study we confirm the similarities between the two Helicoverpa species: armigera and zea by (1) demonstrating the presence of the receptor protein in Sf9 cells, cloned to express the HezPBAN receptor, as compared with the endogenous receptor protein, previously shown in H. armigera pheromone glands, and (2) by identifying the nucleotide sequence of the PBAN-R from mRNA of H. armigera pheromone glands. Sequences of the two Helicoverpa spp. are 98% identical with most changes taking place in the 3,-end. We demonstrate the spatial distribution of the PBAN receptor protein in membranes of H. armigera brain (Br), thoracic ganglion (TG) and ventral nerve cord (VNC). We also demonstrate the presence and differential expression of the PBAN receptor gene (using reverse transcription,polymerase chain reaction and reverse transcription,quantitative real-time polymerase chain reaction, respectively) in the neural tissues (Br, TG and VNC) of adult H. armigera female moths as compared with its presence in pheromone glands. Surprisingly, the gene for the PBAN receptor is also detected in the male tissue homologous to the female pheromone gland, the aedeagus, although the protein is undetectable and PBAN does not induce physiological (pheromone production) or cellular (cyclic-adenosine monophosphate production) responses in this tissue. Our findings indicate that PBAN or PBAN-like receptors are present in the neural tissues and may represent a neurotransmitter-like function for PBAN-like peptides. In addition, the surprising discovery of the presence of the gene encoding the PBAN receptor in the male homologous tissue, but its absence at the protein level, launches opportunities for studying molecular regulation pathways and the evolution of these G protein coupled receptors (GPCRs). [source] Penta-deuterated acid precursors in the pheromone biosynthesis of the Egyptian armyworm, Spodoptera littoralisJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 12 2009Lourdes Muñoz Abstract Synthesis of penta-deuterated intermediate precursors d5(E)-11-14:Acid (7), d5(Z)-11-14:Acid (10) and d514:Acid (12) of the pheromone of the Egyptian armyworm Spodoptera littoralis has been accomplished by a very convenient route starting from the commercially available 9-dodecyn-1-ol. The processes occur with a high to excellent chemical and stereochemical yields and the compounds have been successfully used in the confirmation of the pheromone composition and biosynthesis of our strain. Copyright © 2009 John Wiley & Sons, Ltd. [source] Biosynthetic pathways of the pheromone of the Egyptian armyworm Spodoptera littoralisPHYSIOLOGICAL ENTOMOLOGY, Issue 4 2008LOURDES MUÑOZ Abstract Most insect pheromones comprise multicomponent blends of geometric or optical isomers, and one major question is how insects produce species-specific ratios of components for successful reproductive isolation. Key enzymes suggested to be involved in pheromone biosynthesis are acetyl-coenzyme A carboxylase and fatty acyl synthetase, chain-shortening enzymes, desaturases, elongases, reductases, oxidases, and alcohol acetyl transferases. The female pheromone composition of the Egyptian armyworm Spodoptera littoralis (Boisd.) is highly dependent on the origin of the strain. In this review, we present a summary of the different reported pheromone compositions of the moth, including from our recent studies on this subject, as well as the biosynthetic routes to the different components and the molecular approaches involved. In addition, the key role played in the proposed biosynthetic pathways by a number of important biosynthetic enzymes, such as chain shortening enzymes, desaturases and alcohol acetyl transferases, is outlined, as well as the latest developments on the inhibition of these enzymes. [source] Expression of pheromone biosynthesis activating neuropeptide and its receptor (PBANR) mRNA in adult female Spodoptera exigua (Lepidoptera: Noctuidae)ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 1 2010Yunxia Cheng Abstract The full-length cDNA of pheromone biosynthesis activating neuropeptide receptor (PBANR) was cloned from the beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae); it included an open reading frame of 1,053,bp encoding 350 amino acids. The PBANR of S. exigua (SePBANR) was structurally characteristic of G protein,coupled receptor and its amino acid sequence shared 98% identity with the PBANR of Spodoptera littoralis. Both pheromone biosynthesis activating neuropeptide (PBAN) and PBANR mRNA abundance were measured in the brain-subesophageal ganglion complex, pheromone gland, ventral nerve cord, and ovary of S. exigua female moths by real-time RT-PCR. The abundance of PBAN mRNA in brain-subesophageal ganglion complex and PBANR mRNA in pheromone gland was significantly greater compared to other tissues, suggesting that the ligand-receptor relationship of PBAN and PBANR exists quantitatively in S. exigua. Both PBAN and PBANR expression displayed a remarkable diurnal rhythm, for they were low and stable during the photophase (07:00,21:00) and increased markedly during the scotophase (with a maximum abundance at 23:30) in 3-day-old female moths. The abundance of PBAN and PBANR increased steadily from the 1st day to the 5th day of the adult female life. The pattern of both diurnal and daily expression of PBAN and PBANR mRNA were coincident with enhanced capacity of sex pheromone release and mating of S. exigua moths during the same period. We infer from these results that pheromone biosynthesis and release in S. exigua is regulated by PBAN via up-regulating synthesis. © 2010 Wiley Periodicals, Inc. [source] Regulation of pheromone biosynthesis in the "Z strain" of the European corn borer, Ostrinia nubilalisARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 1 2007H.S. Eltahlawy Abstract The regulation of pheromone biosynthesis by the neuropeptide PBAN in the Z strain of the European corn borer, Ostrinia nubilalis, was investigated using labeled intermediates. Injection of radiolabeled acetate showed PBAN did not influence the de novo synthesis of saturated fatty acids in the gland. When deuterium-labeled myristic acid was topically applied to the gland, females injected with PBAN produced more labeled pheromone than did control females, indicating that PBAN controls one of the later steps of pheromone biosynthesis. Although more myristic acid was ,11-desaturated in the gland in the presence of PBAN, this was counterbalanced by less ,11-desaturation of palmitic acid, indicating that desaturase activity did not change overall. This change in flux of myristic acid through to pheromone was shown to be caused by increased reduction of fatty acid pheromone precursors occurring in the presence of PBAN. Arch. Insect Biochem. Physiol. 65:29,38, 2007. © 2007 Wiley-Liss, Inc. [source] Evidence for two-step regulation of pheromone biosynthesis by the pheromone biosynthesis-activating neuropeptide in the moth Heliothis virescens,ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 3 2007H. Eltahlawy Abstract The control of pheromone biosynthesis by the neuropeptide PBAN was investigated in the moth Heliothis virescens. When decapitated females were injected with [2- 14C] acetate, females co-injected with PBAN produced significantly greater quantities of radiolabeled fatty acids in their pheromone gland than females co-injected with saline. This indicates that PBAN controls an enzyme involved in the synthesis of fatty acids, probably acetyl CoA carboxylase. Decapitated females injected with PBAN showed a rapid increase in native pheromone, and a slower increase in the pheromone precursor, (Z)-11-hexadecenoate. Total native palmitate and stearate (both pheromone intermediates) showed a significant decrease after PBAN injection, before their titers were later restored to initial levels. In contrast, the acyl-CoA thioesters of these two saturated fatty acids increased during the period when their total titers decreased. When a mixture of labeled palmitic and heptadecanoic (an acid that cannot be converted to pheromone) acids was applied to the gland, PBAN-injected females produced greater quantities of labeled pheromone and precursor than did saline-injected ones. The two acids showed similar time-course patterns, with no difference in total titers of each of the respective acids between saline- and PBAN-injected females. When labeled heptadecanoic acid was applied to the gland alone, there was no difference in titers of either total heptadecanoate or of heptadecanoyl-CoA between PBAN- and saline-injected females, suggesting that PBAN does not directly control the storage or liberation of fatty acids in the gland, at least for this fatty acid. Overall, these data indicate that PBAN also controls a later step involved in pheromone biosynthesis, perhaps the reduction of acyl-CoA moieties. The control by PBAN of two enzymes, near the beginning and end of the pheromone biosynthetic process, would seem to allow for more efficient utilization of fatty acids and pheromone than control of only one enzyme. Arch. Insect Biochem. Physiol. 64:120,130, 2007. Published 2007 Wiley-Liss, Inc. [source] Female sex pheromone suppression and the fate of sex-peptide-like peptides in mated moths of Helicoverpa armigeraARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 3 2007V.K. Nagalakshmi Abstract Insect males produce accessory gland (MAG) factors that are transferred in the seminal fluid to females during copulation, and elicit changes in the mated female's behavior and physiology. Our previous studies showed that the injection of synthetic Drosophila melanogaster sex-peptide (DrmSP) into virgin females of the moth Helicoverpa armigera causes a significant inhibition of pheromone production. In this and other moth species, pheromone production, correlated with female receptivity, is under neuroendocrine control due to the circadian release of the neuropeptide PBAN. In this study, we show that PBAN, present in the hemolymph during the scotophase in females, is drastically reduced after mating. We also identify 4 DrmSP-like HPLC peaks (Peaks A, S1, S2, and B) in MAGs, with increasing levels of DrmSP immunoreactivity during the scotophase, when compared to their levels observed during the photophase. In H. armigera MAGs, a significant reduction in the pheromonostatic peak (Peak B) was already evident after 15 min of copulation, and depletion of an additional peak (Peak S2) was evident after complete mating. Peak A is also detected in female brains, increasing significantly 1 h after mating, at which time inhibition of pheromone biosynthesis also occurs. However, changes corresponding to the other MAG peaks were not detected in mated female tissues. Arch. Insect Biochem. Physiol. 64:142,155, 2007. © 2007 Wiley-Liss, Inc. [source] The Pheromone Production of Female Plodia interpunctella Is Inhibited by Tyraminergic AntagonistsCHEMISTRY & BIODIVERSITY, Issue 11 2004Akinori Hirashima Several compounds were found to suppress the calling behavior and in vitro pheromone biosynthesis of the Indian meal moth, Plodia interpunctella. The compounds were screened by means of a calling-behavior bioassay with female P. interpunctella. Five derivatives with activities in the nanomolar range were identified, in order of decreasing pheromonostatic activity: 4-hydroxybenzaldehyde semicarbazone (42) >5-(4-methoxyphenyl)-1,3-oxazole (38) >5-[4-(tert -butyl)phenyl]-1,3-oxazole (40) >5-(3-methoxyphenyl)-1,3-oxazole (35) >5-(4-cyanophenyl)-1,3-oxazole (36). These compounds also showed in vitro inhibitory activity in intracellular de novo pheromone biosynthesis, as determined with isolated pheromone-gland preparations that incorporated [1- 14C]sodium acetate in the presence of the so-called pheromone-biosynthesis-activating neuropeptide (PBAN). The non-additive effect of the inhibitor with antagonist (yohimbine) for the tyramine (TA) receptor suggests that it could be a tyraminergic antagonist. Three-dimensional (3D) computer models were built from a set of compounds. Among the common-featured models generated by the program Catalyst/HipHop, aromatic-ring (AR) and H-bond-acceptor-lipophilic (HBAl) features were considered to be essential for inhibitory activity in the calling behavior and in vitro pheromone biosynthesis. Active compounds, including yohimbine, mapped well onto all the AR and HBAl features of the hypothesis. Less-active compounds were shown to be unable to achieve an energetically favorable conformation, consistent with our 3D common-feature pharmacophore models. The present hypothesis demonstrates that calling behavior and PBAN-stimulated incorporation of radioactivity are inhibited by tyraminergic antagonists. [source] | |||||||||||||