| 1. |
- Jacquin, Emmanuelle, et al.
(author)
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Control of sex pheromone biosynthesis in the moth Mamestra brassicae by the pheromone biosynthesis activating neuropeptide
- 1994
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In: Insect Biochemistry and Molecular Biology. - : Elsevier BV. - 0965-1748. ; 24:2, s. 203-211
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Journal article (peer-reviewed)abstract
- The physiological route for the action of the pheromone biosynthesis activating neuropeptide (PBAN) was determined in Mamestra brassicae (L.) (Lepidoptera:Noctuidae). Removal of the ventral nerve cord including the terminal abdominal ganglia did not affect PBAN stimulation of pheromone production and the biogenic amine octopamine did not stimulate pheromone production in isolated abdomens. PBAN-like activity was found in the hemolymph of intact females in scotophase and not in the hemolymph of decapitated females or females in photophase. Our results suggest that PBAN follows a humoral route to its site of action rather than a neural one after being released from the brain. The hormonal control of the pheromone biosynthetic pathway was investigated using labeled precursors. Our results suggest that PBAN regulates an early step in the pheromone biosynthetic pathway, contrary to a previous report that it stimulates the Δ11-desaturase.
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| 2. |
- Wu, Wenqi, et al.
(author)
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A comparative study of sex pheromone biosynthesis in two strains of the turnip moth, Agrotis segetum, producing different ratios of sex pheromone components
- 1998
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In: Insect Biochemistry and Molecular Biology. - 0965-1748. ; 28:11, s. 895-900
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Journal article (peer-reviewed)abstract
- Among the sex pheromone components of the turnip moth, Agrotis segetum, (Z)-5-decenyl acetate, (Z)-7-dodecenyl acetate and (Z)-9-tetradecenyl acetate are biosynthetically derived from palmitic acid by Δ11-desaturation, chain- shortening, reduction and acetylation. Females of a Zimbabwean population produce the three components in a 78:20:2 ratio, while Swedish females produce the three components in a 12:59:29 ratio. We found that the titers of primary pheromone precursors, such as 16:Acyl and Z11-16:Acyl, did not differ significantly between the two populations. However, the amounts of intermediate precursors Z5-10:Acyl, Z7-12:Acyl and Z9-14:Acyl were significantly higher in the Swedish female extracts. There Was no obvious correlation between the ratios of pheromone precursors and the ratios of pheromone components. By application of D3-16:COOH, D9-Z11-16:COOH, D9- Z9-14:COOH and D9-Z7-12:COOH to the female pheromone glands, we found that Zimbabwean females produced more labelled D9-Z5-10:OAc than Swedish females. In contrast, in Swedish females, the labelled precursors were mainly converted to D9-Z9-14:OAc and D9-Z7-12:OAc, rather than to D9-Z5-10:OAc. Moreover, the conversion rate of D9-Z5-10:COOH to D9-Z5-10:OAc, was significantly higher in Zimbabwean females than in Swedish females. Our results indicate that differences in chain shortening and/or the preferential reduction of acids with different chain lengths may lead to the production of different ratios. Brain-SOG homogenates from the two populations increased the pheromone production of decapitated females of both populations, but did not change the pheromone ratios of the two populations.
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| 3. |
- Zhu, J. W., et al.
(author)
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Reductase specificity and the ratio regulation of E/Z isomers in pheromone biosynthesis of the European corn borer, Ostrinia nubilalis (Lepidoptera Pyralidae)
- 1996
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In: Insect Biochemistry and Molecular Biology. - : Elsevier BV. - 0965-1748. ; 26:2, s. 171-176
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Journal article (peer-reviewed)abstract
- Species specificity of moth sex pheromones is in many cases achieved by means of specific blends rather than by specific components. Two pheromone strains of the European corn borer, Ostrinia nubilalis, use (E)- and (Z)-11-tetradecenyl acetate in different ratios as their pheromone, but show the same ratio of the pheromone precursors (70:30 E/Z-11-tetradecenoic acid). The hypothesis that the ratio of the pheromone components in the two strains and their hybrids is controlled by the specificity of the reductase system, responsible for conversion of acid to the corresponding alcohol precursors, was tested. Deuterium-labeled alcohols, aldehydes and fatty acids corresponding to the two pheromone components were topically applied to the pheromone glands in different ratios and their selective incorporation into pheromone components was determined by gas chromatography with mass selective detection. Acetylation of the (E)- and (Z)-11-tetradecenols was unselective, whereas the corresponding aldehydes and acids were selectively incorporated into the pheromone components. Z strain females selectively metabolized the Z-isomers whereas E strain females converted the E-isomers. The E strain being the most selective of the two strains. Hybrids converted both geometric isomers. The relative conversion rate of both E- and Z-isomers of all tetradecenoic acids with the double bond in positions from 7-12, was also determined. In addition to the Δ11-isomers, the E strain females converted (E)-8-tetradecenoic acid into acetate and the Z strain females converted (E)-12-tetradecenoic acid. None of these substrates occur naturally in the pheromone gland, but (E)-12-tetradecenyl acetate is a pheromone component of the Asian corn borer O. furnacalis. Thus the possibility for conversion of (E)-12-tetradecenoic acid to acetate in the Z strain, as well as the earlier reported conversion of (Z)-11-tetradecenoic acid to acetate in O. furnacalis, suggests that O. furnacalis is closest related to the Z strain of O. nubilalis.
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| 4. |
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| 5. |
- Theopold, Ulrich, et al.
(author)
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Changes in glycosylation during Drosophila development. : The influence of ecdysone on hemomucin isoforms
- 2001
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In: Insect Biochemistry and Molecular Biology. - 0965-1748 .- 1879-0240. ; 31:2, s. 189-197
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Journal article (peer-reviewed)abstract
- To explore a possible signal function of glycodeterminants and the tissue specificity of glycosylation in Drosophila melanogaster, hemomucin, a surface mucin previously isolated from cell lines was studied. It was shown to exist in two glycoforms with molecular masses of 100 and 105 kDa, respectively. The two forms differ by the presence of O-linked galactose, which was only detected in the larger glycoform using the β-galactose specific peanut agglutinin (PNA). The 105 form was found in cell lines after addition of the cell cycle inhibitor taxol and after induction with ecdysone. When whole animal tissues were analyzed using PNA, dramatic changes were observed during development. We were able to identify a number of proteins, which showed strong PNA-staining in stages with a high ecdysone titer, while virtually no staining was detected in adults. This pattern was specific for PNA and was not observed with any of the other lectins employed in this study. Surprisingly, in contrast to our observation in cell lines, PNA staining of hemomucin was not observed in late third larval and pupal stages, which are known to produce high ecdysone titers. The only organ, in which significant amounts of the 105 form were detected, were the ovaries, where hemomucin is produced in follicle cells during the late phase of oogenesis and subsequently incorporated into the chorion.
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| 6. |
- Abraham, David, et al.
(author)
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Molecular characterization and evolution of pheromone binding protein genes in Agrotis moths
- 2005
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In: Insect Biochemistry and Molecular Biology. - : Elsevier BV. - 1879-0240 .- 0965-1748. ; 35:10, s. 1100-1111
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Journal article (peer-reviewed)abstract
- Pheromone-binding proteins (PBPs) are soluble transporter proteins that increase the capture and the solubilization of pheromone molecules in the lymph surrounding the olfactory receptors. A polymerase chain reaction-based method was used to identify PBP genes in Agrotis species for an evolutionary genomic study of noctuid moth PBPs. From genomic DNA we determined the structure of different PBP genes in the two closely related species, Agrotis ipsilon and A. segetum. In all, we clearly identified four genes (Aips-1, Aips-2, Aseg-1 and Asey-2) that represent two distinct PBP orthology groups. We found that the four genes have the same exon-intron structure and that they comprise three exons and two introns but differ in length mainly in the second intron. The three exons of Aseg-2 and Aips-2 have the same lengths but both intron I and intron 2 differ in length between the genes. In contrast, Aips-1 and Aseg-1 show dissimilarity only in the length of intron 2. Interestingly, introns 1 and 2 are inserted in the same positions in the Aips-1, Aips-2, Aseg-1 and Aseg-2 genes. These findings show that the Agrotis PBP genes have common ancestry and probably originate from gene duplication before the speciation of ipsilon and segetum. We found that expression of Aips-1/Aseg-1 and Aips-2/ Aseg-2 is antennal-specific, but expression is not restricted to the inale antennae. (c) 2005 Elsevier Ltd. All rights reserved.
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| 7. |
- Ardell, DH, et al.
(author)
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Tentative identification of a resilin gene in Drosophila melanogaster
- 2001
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In: INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0965-1748. ; 31:10, s. 965-970
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Journal article (peer-reviewed)abstract
- A search of the Drosophila genome for gene products with similarities to the amino acid sequences of three tryptic peptides from locust (Schistocerca gregaria) resilin gave two positive results: gene products CG15920 and CG9036. In both conceptual transla
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| 8. |
- Bayram, Helen L., et al.
(author)
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Identification of novel ejaculate proteins in a seed beetle and division of labour across male accessory reproductive glands
- 2019
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In: Insect biochemistry and molecular biology. - : Pergamon. - 0965-1748 .- 1879-0240. ; 104, s. 50-57
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Journal article (peer-reviewed)abstract
- The male ejaculate contains a multitude of seminal fluid proteins (SFPs), many of which are key reproductive molecules, as well as sperm. However, the identification of SFPs is notoriously difficult and a detailed understanding of this complex phenotype has only been achieved in a few model species. We employed a recently developed proteomic method involving whole-organism stable isotope labelling coupled with proteomic and transcriptomic analyses to characterize ejaculate proteins in the seed beetle Callosobruchus maculatus. We identified 317 proteins that were transferred to females at mating, and a great majority of these showed signals of secretion and were highly male-biased in expression in the abdomen. These male-derived proteins were enriched with proteins involved in general metabolic and catabolic processes but also with proteolytic enzymes and proteins involved in protection against oxidative stress. Thirty-seven proteins showed significant homology with SFPs previously identified in other insects. However, no less than 92 C. maculatus ejaculate proteins were entirely novel, receiving no significant blast hits and lacking homologs in extant data bases, consistent with a rapid and divergent evolution of SFPs. We used 3D micro-tomography in conjunction with proteomic methods to identify 5 distinct pairs of male accessory reproductive glands and to show that certain ejaculate proteins were only recovered in certain male glands. Finally, we provide a tentative list of 231 candidate female-derived reproductive proteins, some of which are likely important in ejaculate processing and/or sperm storage.
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| 9. |
- Becher, Paul
(author)
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Functional transcriptome analyses of Drosophila suzukii antennae reveal mating-dependent olfaction plasticity in females
- 2019
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In: Insect Biochemistry and Molecular Biology. - : Elsevier BV. - 0965-1748 .- 1879-0240. ; 105, s. 51-59
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Journal article (peer-reviewed)abstract
- Insect olfaction modulates basal behaviors and it is often influenced by the physiological condition of each individual such as the reproductive state. Olfactory plasticity can be achieved by modifications at both peripheral and central nervous system levels. Here we performed a genome-wide transcriptomic analysis of the main olfactory organ, the antenna, to investigate how gene expression varies with female mating status in Drosophila suzukii, a destructive and invasive soft fruit pest. We observed a wide mating-induced up-regulation of chemosensory-related genes in females, especially odorant receptor (Or) genes. We then used a candidate gene approach to define the comprehensive dataset of antenna-expressed chemosensory receptors and binding proteins, which showed many similarities with Drosophila melanogaster. Candidate gene approach was also used to finely quantify differential expression at Or isoform level, suggesting post-mating transcriptional modulation of genes involved in the peripheral olfactory system. We identified 27 up-regulated Or transcripts encoded by 25 genes, seven of them were duplications specific to D. suzukii lineage. Post-mating olfactory modulation was further supported by electroantennogram recordings that showed a differential response according to mating status to one out of eight odors tested (isoamyl-acetate). Our study characterizes the transcriptional mechanisms driven by mating in D. suzukii female antennae. Understanding the role of genes differentially expressed in virgin or mated females will be crucial to better understand host finding and the crop-damaging oviposition behavior of this species.
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| 10. |
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