| 1. |
- Ding, Baojian, et al.
(författare)
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Sequence variation determining stereochemistry of a delta-11 desaturase active in moth sex pheromone biosynthesis
- 2016
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Ingår i: Insect Biochemistry and Molecular Biology. - : Elsevier BV. - 1879-0240 .- 0965-1748. ; 74, s. 68-75
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Tidskriftsartikel (refereegranskat)abstract
- A Δ11 desaturase from the oblique banded leaf roller moth Choristoneura rosaceana takes the saturated myristic acid and produces a mixture of (E)-11-tetradecenoate and (Z)-11-tetradecenoate with an excess of the Z isomer (35:65). A desaturase from the spotted fireworm moth Choristoneura parallela also operates on myristic acid substrate but produces almost pure (E)-11-tetradecenoate. The two desaturases share 92% amino acid identity and 97% amino acid similarity. There are 24 amino acids differing between these two desaturases. We constructed mutations at all of these positions to pinpoint the sites that determine the product stereochemistry. We demonstrated with a yeast functional assay that one amino acid at the cytosolic carboxyl terminus of the protein (258E) is critical for the Z activity of the C. rosaceana desaturase. Mutating the glutamic acid (E) into aspartic acid (D) transforms the C. rosaceana enzyme into a desaturase with C. parallela-like activity, whereas the reciprocal mutation of the C. parallela desaturase transformed it into an enzyme producing an intermediate 64:36 E/Z product ratio. We discuss the causal link between this amino acid change and the stereochemical properties of the desaturase and the role of desaturase mutations in pheromone evolution.
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| 2. |
- Yuvaraj, Jothi Kumar, et al.
(författare)
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Characterization of odorant receptors from a non-ditrysian moth, Eriocrania semipurpurella sheds light on the origin of the sex pheromone receptors in Lepidoptera
- 2017
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Ingår i: Molecular biology and evolution. - : Oxford University Press (OUP). - 0737-4038 .- 1537-1719. ; 34:11, s. 2733-2746
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Tidskriftsartikel (refereegranskat)abstract
- Pheromone receptors (PRs) are essential in moths to detect sex pheromones for mate finding. However, it remainsunknown from which ancestral proteins these specialized receptors arose. The oldest lineages of moths, so-callednon-ditrysian moths, use short-chain pheromone components, secondary alcohols, or ketones, so called Type 0 pheromonesthat are similar to many common plant volatiles. It is, therefore, possible that receptors for these ancestralpheromones evolved from receptors detecting plant volatiles. Hence, we identified the odorant receptors (ORs) from anon-ditrysian moth, Eriocrania semipurpurella (Eriocraniidae, Lepidoptera), and performed functional characterizationof ORs using HEK293 cells. We report the first receptors that respond to Type 0 pheromone compounds; EsemOR3displayed highest sensitivity toward (2S, 6Z)-6-nonen-2-ol, whereas EsemOR5 was most sensitive to the behavioralantagonist (Z)-6-nonen-2-one. These receptors also respond to plant volatiles of similar chemical structures, but withlower sensitivity. Phylogenetically, EsemOR3 and EsemOR5 group with a plant volatile-responding receptor from thetortricid moth Epiphyas postvittana (EposOR3), which together reside outside the previously defined lepidopteran PRclade that contains the PRs from more derived lepidopteran families. In addition, one receptor (EsemOR1) that falls atthe base of the lepidopteran PR clade, responded specifically to b-caryophyllene and not to any other additional plant orpheromone compounds. Our results suggest that PRs for Type 0 pheromones have evolved from ORs that detectstructurally-related plant volatiles. They are unrelated to PRs detecting pheromones inmore derived Lepidoptera, which,in turn, also independently may have evolved a novel function from ORs detecting plant volatiles.
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| 3. |
- Yuvaraj, Jothi K., et al.
(författare)
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Putative ligand binding sites of two functionally characterized bark beetle odorant receptors
- 2021
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Ingår i: BMC Biology. - : Springer Science and Business Media LLC. - 1741-7007. ; 19
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Tidskriftsartikel (refereegranskat)abstract
- Background: Bark beetles are major pests of conifer forests, and their behavior is primarily mediated via olfaction. Targeting the odorant receptors (ORs) may thus provide avenues towards improved pest control. Such an approach requires information on the function of ORs and their interactions with ligands, which is also essential for understanding the functional evolution of these receptors. Hence, we aimed to identify a high-quality complement of ORs from the destructive spruce bark beetle Ips typographus (Coleoptera, Curculionidae, Scolytinae) and analyze their antennal expression and phylogenetic relationships with ORs from other beetles. Using 68 biologically relevant test compounds, we next aimed to functionally characterize ecologically important ORs, using two systems for heterologous expression. Our final aim was to gain insight into the ligand-OR interaction of the functionally characterized ORs, using a combination of computational and experimental methods. Results: We annotated 73 ORs from an antennal transcriptome of I. typographus and report the functional characterization of two ORs (ItypOR46 and ItypOR49), which are responsive to single enantiomers of the common bark beetle pheromone compounds ipsenol and ipsdienol, respectively. Their responses and antennal expression correlate with the specificities, localizations, and/or abundances of olfactory sensory neurons detecting these enantiomers. We use homology modeling and molecular docking to predict their binding sites. Our models reveal a likely binding cleft lined with residues that previously have been shown to affect the responses of insect ORs. Within this cleft, the active ligands are predicted to specifically interact with residues Tyr84 and Thr205 in ItypOR46. The suggested importance of these residues in the activation by ipsenol is experimentally supported through site-directed mutagenesis and functional testing, and hydrogen bonding appears key in pheromone binding. Conclusions: The emerging insight into ligand binding in the two characterized ItypORs has a general importance for our understanding of the molecular and functional evolution of the insect OR gene family. Due to the ecological importance of the characterized receptors and widespread use of ipsenol and ipsdienol in bark beetle chemical communication, these ORs should be evaluated for their potential use in pest control and biosensors to detect bark beetle infestations.
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| 4. |
- Zhang, Dan-Dan, et al.
(författare)
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Receptor for detection of a Type II sex pheromone in the winter moth Operophtera brumata
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- How signal diversity evolves under stabilizing selection in a pheromone-based mate recognitionsystem is a conundrum. Female moths produce two major types of sex pheromones, i.e., long-chainacetates, alcohols and aldehydes (Type I) and polyenic hydrocarbons and epoxides (Type II), alongdifferent biosynthetic pathways. Little is known on how male pheromone receptor (PR) genes evolvedto perceive the different pheromones. We report the identification of the first PR tuned to Type IIpheromones, namely ObruOR1 from the winter moth, Operophtera brumata (Geometridae). ObruOR1clusters together with previously ligand-unknown orthologues in the PR subfamily for the ancestralType I pheromones, suggesting that O. brumata did not evolve a new type of PR to match the novel TypeII signal but recruited receptors within an existing PR subfamily. AsegOR3, the ObruOR1 orthologuepreviously cloned from the noctuid Agrotis segetum that has Type I acetate pheromone components,responded significantly to another Type II hydrocarbon, suggesting that a common ancestor with TypeI pheromones had receptors for both types of pheromones, a preadaptation for detection of Type II sexpheromone.
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| 5. |
- Sadek, Medhat, et al.
(författare)
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Modulation of the temporal pattern of calling behavior of female Spodoptera littoralis by exposure to sex pheromone
- 2012
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Ingår i: Journal of Insect Physiology. - : Elsevier BV. - 1879-1611 .- 0022-1910. ; 58, s. 61-66
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Tidskriftsartikel (refereegranskat)abstract
- We have examined the timing of calling behavior in the female Egyptian cotton leafworm, Spodoptera littoralis and its modification by exposure to sex pheromone. The calling rhythm of the female moth was found to be circadian, persistent for at least 4days once it has been entrained, and could be phase shifted by altering the light:dark regime. We also found that female exposure to pheromone affected the rate and duration of calling. A brief exposure to pheromone gland extract increased the proportion of females calling in a constant dim light and this effect persisted for at least 2days. In response to pheromone exposure, significantly more females also called late into scotophase when most unexposed control females had ceased calling. The adaptive significance of responding to conspecific sex pheromone is discussed.
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| 6. |
- Wang, Hong-Lei, et al.
(författare)
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Identification of the sex pheromone of the spruce seed moth, Cydia strobilella L.
- 2010
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Ingår i: Journal of Chemical Ecology. - : Springer Science and Business Media LLC. - 1573-1561 .- 0098-0331. ; 36:3, s. 305-313
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Tidskriftsartikel (refereegranskat)abstract
- The spruce seed moth, Cydia strobilella L., is a serious pest on cones of spruce (Picea spp.) in the Holarctic region. Previous studies from different parts of its area of distribution have reported conflicting results on the composition of its sex pheromone. By gas chromatography with electroantennographic detection, coupled gas chromatography-mass spectrometry, a Y-tube olfactometer bioassay, and field trials, the sex pheromone of Swedish populations of the species was identified as (8E,10E)-dodecadienyl acetate and (8E,10Z)-dodecadienyl acetate. About 0.5 pg of each pheromone component was extracted per female. The most attractive blend of EE- and EZ-isomers was about 6:4, respectively, and 0.3 microg of the blend per rubber septum was the most attractive dosage for field trapping. Monounsaturated components previously reported as sex pheromone components/attractants for C. strobilella, (E)-8-dodecenyl acetate in Canadian populations and (Z)-8-dodecenol in Polish and Dutch populations, did not attract any C. strobilella in this study. Large numbers of C. jungiella Clerck were trapped by using (8E,10Z)-dodecadienyl acetate alone, whereas (Z)-8-dodecenol attracted Pammene splendidulana Guenée and P. rhediella Clerck.
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| 7. |
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| 8. |
- Xia, Yihan, 1990, et al.
(författare)
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Release of moth pheromone compounds from Nicotiana benthamiana upon transient expression of heterologous biosynthetic genes
- 2022
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Ingår i: BMC Biology. - : Springer Science and Business Media LLC. - 1741-7007. ; 20:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Using genetically modified plants as natural dispensers of insect pheromones may eventually become part of a novel strategy for integrated pest management. Results: In the present study, we first characterized essential functional genes for sex pheromone biosynthesis in the rice stem borer Chilo suppressalis (Walker) by heterologous expression in Saccharomyces cerevisiae and Nicotiana benthamiana, including two desaturase genes CsupYPAQ and CsupKPSE and a reductase gene CsupFAR2. Subsequently, we co-expressed CsupYPAQ and CsupFAR2 together with the previously characterized moth desaturase Atr∆11 in N. benthamiana. This resulted in the production of (Z)-11-hexadecenol together with (Z)-11-hexadecenal, the major pheromone component of C. suppressalis. Both compounds were collected from the transformed N. benthamiana headspace volatiles using solid-phase microextraction. We finally added the expression of a yeast acetyltransferase gene ATF1 and could then confirm also (Z)-11-hexadecenyl acetate release from the plant. Conclusions: Our results pave the way for stable transformation of plants to be used as biological pheromone sources in different pest control strategies.
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| 9. |
- Hou, Xiao-Qing, et al.
(författare)
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Functional Evolution of a Bark Beetle Odorant Receptor Clade Detecting Monoterpenoids of Different Ecological Origins
- 2021
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Ingår i: Molecular biology and evolution. - : Oxford University Press. - 0737-4038 .- 1537-1719. ; 38:11, s. 4934-4947
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Tidskriftsartikel (refereegranskat)abstract
- Insects detect odors using an array of odorant receptors (ORs), which may expand through gene duplication. How and which new functions may evolve among related ORs within a species remain poorly investigated. We addressed this question by functionally characterizing ORs from the Eurasian spruce bark beetle Ips typographus, in which physiological and behavioral responses to pheromones, volatiles from host and nonhost trees, and fungal symbionts are well described. In contrast, knowledge of OR function is restricted to two receptors detecting the pheromone compounds (S)-(-)-ipsenol (ItypOR46) and (R)-(-)-ipsdienol (ItypOR49). These receptors belong to an Ips-specific OR-lineage comprising seven ItypORs. To gain insight into the functional evolution of related ORs, we characterized the five remaining ORs in this Glade using Xenopus oocytes. Two receptors responded primarily to the host tree monoterpenes (+)-3-carene (ItypOR25) and p-cymene (ItypOR27). Two receptors responded to oxygenated monoterpenoids produced in larger relative amounts by the beetle-associated fungi, with ItypOR23 specific for (+)-trans-(1R, 4S)-4-thujanol, and ItypOR29 responding to (+)-isopinocamphone and similar ketones. ItypOR28 responded to the pheromone E-myrcenol from the competitor Ips duplicatus. Overall, the OR responses match well with those of previously characterized olfactory sensory neuron classes except that neurons detecting E-myrcenol have not been identified. The characterized ORs are under strong purifying selection and demonstrate a shared functional property in that they all primarily respond to monoterpenoids. The variation in functional groups among OR ligands and their diverse ecological origins suggest that neofunctionalization has occurred early in the evolution of this OR-lineage following gene duplication.
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| 10. |
- Powell, Daniel, et al.
(författare)
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A highly-contiguous genome assembly of the Eurasian spruce bark beetle, Ips typographus, provides insight into a major forest pest
- 2021
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- Conifer-feeding bark beetles are important herbivores and decomposers in forest ecosystems. These species complete their life cycle in nutritionally poor substrates and some can kill enormous numbers of trees during population outbreaks. The Eurasian spruce bark beetle (Ips typographus) can destroy >100 million m3 of spruce in a single year. We report a 236.8 Mb I. typographus genome assembly using PacBio long-read sequencing. The final phased assembly has a contig N50 of 6.65 Mb in 272 contigs and is predicted to contain 23,923 protein-coding genes. We reveal expanded gene families associated with plant cell wall degradation, including pectinases, aspartyl proteases, and glycosyl hydrolases. This genome sequence from the genus Ips provides timely resources to address questions about the evolutionary biology of the true weevils (Curculionidae), one of the most species-rich animal families. In forests of today, increasingly stressed by global warming, this draft genome may assist in developing pest control strategies to mitigate outbreaks.
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