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1.
J Agric Food Chem ; 69(1): 55-66, 2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33356240

RESUMO

Hyphantria cunea (Drury) is a destructive invasive pest species in China that uses type II sex pheromone components. To date, however, the binding mechanisms of its sex pheromone components to their respective pheromone-binding proteins (HcunPBPs 1/2/3) have not been explored. In the current study, all three HcunPBPs were expressed in the antennae of both sexes. The prokaryotic expression and ligand binding assays were employed to study the binding of the moth's four sex pheromone components, including two aldehydes and two epoxides, and 24 plant volatiles to the HcunPBPs. Our results showed that the abilities of these HcunPBPs to bind to the aldehydes were significantly different from binding to the epoxides. These three HcunPBPs also selectively bind to some of the plant volatiles tested. Our molecular docking results indicated that some crucial hydrophobic residues might play a role in the binding of HcunPBPs to their sex pheromone components. Three HcunPBPs have different selectivities for pheromone components with both major and minor structural differences. Our study provides a fundamental insight into the olfactory mechanism of moths at the molecular level, especially for moth species that use various type II pheromone components.

2.
Curr Biol ; 30(22): 4476-4482.e5, 2020 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-32916118

RESUMO

Glucosinolates (GSs) are sulfur-containing secondary metabolites characteristic of cruciferous plants [1, 2]. Their breakdown products, isothiocyanates (ITCs), are released following tissue disruption by insect feeding or other mechanical damages [3, 4]. ITCs repel and are toxic to generalist herbivores, while specialist herbivores utilize the volatile ITCs as key signals for localizing host plants [5, 6]. However, the molecular mechanisms underlying detection of ITCs remain open. Here, we report that in the diamondback moth Plutella xylostella, a crucifer specialist, ITCs indeed drive the host preference for Arabidopsis thaliana, and the two olfactory receptors Or35 and Or49 are essential for this behavior. By performing gene expression analyses, we identified 12 (out of 59 in total) female-biased Ors, suggesting their possible involvement in oviposition choice. By ectopically expressing these Ors in Xenopus oocytes and screening their responses with 49 odors (including 13 ITCs, 25 general plant volatiles, and 11 sex pheromone components), we found that Or35 and Or49 responded specifically to three ITCs (iberverin, 4-pentenyl ITC, and phenylethyl ITC). The same ITCs also exhibited highest activity in electroantennogram recordings with female antennae and were the strongest oviposition stimulants. Knocking out either Or35 or Or49 via CRISPR-Cas9 resulted in a reduced oviposition preference for the ITCs, while double Or knockout females lost their ITC preference completely and were unable to choose between wild-type A. thaliana and a conspecific ITC knockout plant. We hence conclude that the ITC-based oviposition preference of the diamondback moth for its host A. thaliana is governed by the cooperation of two highly specific olfactory receptors.

3.
Pestic Biochem Physiol ; 164: 173-182, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32284124

RESUMO

Athetis lepigone (Alep) is a polyphagous pest native to Europe and Asia that has experienced major outbreaks in the summer maize area of China since 2011 and has shown evidence of resistance to some insecticides. Insect olfaction is crucial for recognition of sex pheromones, host plant volatiles and even insecticides, in which two general-odorant binding proteins (GOBPs) play important roles. To elucidate the functions of GOBPs in A. lepigone, we first expressed the two AlepGOBP proteins in the E. coli expression system. Then, the results of fluorescence competitive binding assays demonstrated that the high binding affinity of AlepGOBP2 with sex pheromones [(Z)-7-dodecenyl acetate (Z7-12:Ac), Ki = 0.65 µM; (Z)-9-tetradecenyl acetate (Z9-14:Ac), Ki = 0.83 µM], two maize plant volatiles [Ocimene, Ki = 9.63 µM; (E)-ß-Farnesene, Ki = 4.76 µM] and two insecticides (Chlorpyrifos Ki =5.61 µM; Phoxim, Ki = 4.38 µM). However, AlepGOBP1 could only bind Ocimene (Ki = 13.0 µM) and two insecticides (Chlorpyrifos Ki =4.46 µM; Phoxim, Ki = 3.27 µM). These results clearly suggest that AlepGOBP1 and AlepGOBP2 differentiate among odorants and other ligands. The molecular docking results further revealed different key residues involved in the ligand binding of AlepGOBPs. In summary, this study provides a foundation for exploring the olfactory mechanism of A. lepigone and identified two potential target genes for the development of highly effective insecticides in the future.


Assuntos
Inseticidas , Mariposas , Atrativos Sexuais , Animais , China , Escherichia coli , Proteínas de Insetos , Simulação de Acoplamento Molecular , Odorantes , Feromônios
4.
Pestic Biochem Physiol ; 164: 7-13, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32284139

RESUMO

Insect gustatory system plays important roles in multiple behaviors including feeding, mating, and oviposition. Gustatory receptors (GRs), located on the dendritic membrane of gustatory sensory neurons (GSNs), are crucial in peripheral coding of non-volatile compounds. However, GRs and their detailed functions remain poorly understood in lepidopteran pests. In the present work, focusing on GR genes of Plutella xylostella, an important worldwide crop pest, we cloned a candidate fructose GR gene that has two spliced variants (PxylGR43a-1 and PxylGR43a-2), and determined the tissue expression profiles by semi-quantitative reverse transcription PCR (RT-PCR). It revealed that both GR variants were highly expressed in antennae and less highly in heads of adults, while PxylGR43a-2 was also weakly expressed in other tested tissues. Functional analyses were further conducted using the Xenopus oocyte system. PxylGR43a-1 and PxylGR43a-2 both responded specifically to the d-fructose among the 12 tested sugar compounds, but PxylGR43a-2 showed much higher current response than PxylGR43a-1. In addition, the proboscis extension reflex (PER) assay was conducted, demonstrating that female moths could respond to d-fructose following stimulation of antenna. Taken together, our study contributes to elucidation of the molecular mechanisms of fructose reception and provides a potential target for development of GR based pest control techniques.


Assuntos
Proteínas de Drosophila , Mariposas , Animais , Feminino , Frutose , Oviposição
5.
Insects ; 11(3)2020 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-32197457

RESUMO

Pheromone receptors (PRs) found in the antennae of male moths play a vital role in the recognition of sex pheromones released by females. The fall armyworm (FAW), Spodoptera frugiperda, is a notorious invasive pest, but its PRs have not been reported. In this report, six candidate PRs (SfruOR6, 11, 13, 16, 56 and 62) suggested by phylogenetic analysis were cloned, and their tissue-sex expression profiles were determined by quantitative real-time PCR (qPCR). All six genes except for SfruOR6 were highly and specifically expressed in the antennae, with SfruOR6, 13 and 62 being male-specific, while the other three (SfruOR11, 16 and 56) were male biased, suggesting their roles in sex pheromone perception. A functional analysis by the Xenopus oocyte system further demonstrated that SfruOR13 was highly sensitive to the major sex pheromone component Z9-14:OAc and the pheromone analog Z9,E12-14:OAc, but less sensitive to the minor pheromone component Z9-12:OAc; SfruOR16 responded weakly to pheromone component Z9-14:OAc, but strongly to pheromone analog Z9-14:OH; the other four candidate PRs did not respond to any of the four pheromone components and four pheromone analogs. This study contributes to clarifying the pheromone perception in the FAW, and provides potential gene targets for developing OR-based pest control techniques.

7.
Front Physiol ; 10: 1256, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31611820

RESUMO

Spodoptera exigua and S. litura are two sympatric species in China and many other countries. Both moths employ a multiple component sex pheromone blend, including a common component Z9,E12-14:OAc, and two specific components Z9-14:OH and Z11-16:OAc for S. exigua, and one specific component Z9,E11-14:OAc for S. litura. For the two species, it has been well documented that males are able to recognize and behaviorally attracted by their species-specific sex pheromone, which functions as a means of reproductive isolation, but whether males could mutually recognize pheromone components of its sympatric species is unknown. In the present study, the electroantennogram (EAG) and field evaluation were conducted to address this topic. The EAG recordings revealed that males of each species could significantly respond to specific components of its sympatric species, although the response values were lower than that to its own major component. In field tests, the specific components Z9-14:OH and Z11-16:OAc of S. exigua strongly inhibited the male catches of S. litura to its conspecific sex pheromone, while specific component Z9,E11-14:OAc of S. litura significantly reduced the male catches of S. exigua to its sex pheromone. Furthermore, the combined lure of the two species completely inhibited male catches of S. litura, and significantly decreased the male catches of S. exigua, compared to the species-specific lure alone. The results demonstrated that males of the two sibling species could perceive the specific components of its counterpart, suggesting that mutual recognition of pheromone components may function to strengthen the behavioral isolation between the two species. Our study has added new knowledge to the reproductive isolation via sex pheromone communication system in sympatric moth species, and provided a base for designing of mating disruption tactics targeting multispecies by using insect sex pheromones.

8.
Insect Biochem Mol Biol ; 115: 103244, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31560967

RESUMO

Three different pheromone binding proteins (PBPs) can typically be found in the sensilla lymph of noctuid moth antennae, but their relative contributions in perception of the sex pheromone is rarely verified in vivo. Previously, we demonstrated that SlitPBP3 plays a minor role in the sex pheromone detection in Spodoptera litura using the CRISPR/Cas9 system. In the present study, the roles of two other SlitPBPs (SlitPBP1 and SlitPBP2) are further verified using the same system. First, by co-injection of Cas9 mRNA/sgRNA into newly laid eggs, a high rate of target mutagenesis was induced, 51.5% for SlitPBP1 and 46.8% for SlitPBP2 as determined by restriction enzyme assay. Then, the homozygous SlitPBP1 and SlitPBP2 knockout lines were obtained by cross-breeding. Finally, using homozygous knockout male moths, we performed electrophysiological (EAG recording) and behavioral analyses. Results showed that knockout of either SlitPBP1 or SlitPBP2 in males decreased EAG response to each of the 3 sex pheromone components (Z9,E11-14:Ac, Z9,E12-14:Ac and Z9-14:Ac) by 53%, 60% and 63% (for SlitPBP1 knockout) and 40%, 43% and 46% (for SlitPBP2 knockout), respectively. These decreases in EAG responses were similar among 3 pheromone components, but were more pronounced in SlitPBP1 knockout males than in SlitPBP2 knockout males. Consistently, behavioral assays with the major component (Z9,E11-14:Ac) showed that SlitPBP1 knockout males responded in much lower percentages than SlitPBP2 knockout males in terms of orientation to the pheromone, along with reduction in close range behaviors such as hairpencil display and mating attempt. Taken together, this study provides direct functional evidence for the roles of SlitPBP1 and SlitPBP2, as well as their relative importance (SlitPBP1 > SlitPBP2) in the sex pheromone perception. This information is valuable in understanding mechanisms of sex pheromone perception and may facilitate the development of PBP-targeted pest control techniques.


Assuntos
Comunicação Animal , Antenas de Artrópodes/fisiologia , Proteínas de Transporte/fisiologia , Proteínas de Insetos/fisiologia , Percepção Olfatória , Spodoptera/fisiologia , Animais , Sequência de Bases , Sistemas CRISPR-Cas , Feminino , Masculino , Mutação , Atrativos Sexuais
9.
Insects ; 10(9)2019 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-31454982

RESUMO

Gustatory receptors (GRs) are crucial in the peripheral coding of the non-volatile compounds in insects, and thus play important roles in multiple behaviors including feeding, mating, and oviposition. However, little research has been done on GRs in lepidopteran pests. In the current work with Spodoptera litura, an important worldwide crop's pest, a candidate fructose GR gene (SlitGR8) was cloned in full length, and its spatial and temporal expression profiles were determined by quantitative real-time PCR (qPCR). It revealed that SlitGR8 was highly expressed in antennae of both male and female adults, as well as in larva of first, fifth and sixth instar. Functional analyses were further conducted using the Xenopus oocyte system. SlitGR8 responded specifically to D-fructose among 12 tested sugar compounds. In addition, the behavioral assay demonstrated that both female and male moths could respond with proboscis extension behavior to D-fructose applied onto the antenna, but females showed higher sensitivity than males. The results provide an important base for further elucidation of molecular mechanisms of gustation, and a potential target for development of feeding interfering technique in S. litura.

10.
Ying Yong Sheng Tai Xue Bao ; 30(7): 2447-2456, 2019 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-31418248

RESUMO

The static chamber-gas chromatography method was applied to observe CO2 fluxes across the water-air interface from different aquaculture systems, including four groups of mesocosms, i.e., blank control system (CK), monoculture system of Sebastes schlegelii (F), monoculture system of Chlamys farreri (B) and polyculture system of S. schlegelii and C. farreri (FB). Meanwhile, the physical, chemical and biological indices of the water were measured. The results showed that the group CK was a stable CO2 source, with the mean flux of 12.42 mg·m-2·h-1. The group B was a CO2 source during the early and middle periods of the experiment and a CO2 sink at the end of the experiment, with the mean flux during the experiment being 10.95 mg·m-2·h-1. The change trends of CO2 flux in the group F and FB were generally consistent, acting as CO2 sources in the early period and as CO2 sinks subsequently. The mean fluxes of those two groups during the expe-riment were -3.53 and -10.49 mg·m-2·h-1, respectively. Water pH was a good predictor for CO2 flux across the water-air interface according to the result of regression analysis, with pH value of 8.25 as the critical threshold between efflux and influx. The net primary production of water column was the main factor influencing the CO2 flux, indicating that phytoplankton might be the main internal force regulating the CO2 flux across the water-air interface. Our results indicated that C. farreri at present stocking density in the polyculture system could promote phytoplankton biomass as well as primary production and therefore enhance the CO2 sink function.


Assuntos
Poluentes Atmosféricos/análise , Aquicultura , Dióxido de Carbono/análise , Pectinidae , Animais , Metano , Água
11.
Pestic Biochem Physiol ; 158: 69-76, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31378363

RESUMO

Sex pheromones are crucial for communication between females and males in moths, and pheromone receptors (PRs) play a key role in peripheral coding of sex pheromones. During the last decade, many PR candidates have been identified based on transcriptome sequencing and bioinformatic analysis, but their detailed functions remain mostly unknown. Here, focusing on four PR candidates of Athetis dissimilis (AdisOR1, AdisOR6, AdisOR11 and AdisOR14) identified in a previous study, we first cloned the full-length cDNAs and determined the tissue expression profiles by quantitative real-time PCR (qPCR). The results revealed that expression of three of these genes were male antennae-specific, while AdisOR11 was similar in expression between male and female antennae. Furthermore, the expression level of AdisOR1 was much higher than those of the other three genes. Then, functional analysis was conducted using Xenopus oocyte system. AdisOR1 responded strongly to the sex pheromone component Z9-14:OH and the potential pheromone component Z9,E12-14:OH, suggesting its important role in the sex pheromone perception; AdisOR14 showed specificity for Z9,E12-14:OH; while AdisOR6 and AdisOR11 did not respond to any of the pheromone components and analogs tested. Taken together, this study contributes to elucidate the molecular mechanism of sex pheromone reception and provides potential targets for development of OR based pest control techniques in A. dissimilis.


Assuntos
Proteínas de Insetos/metabolismo , Lepidópteros/metabolismo , Receptores de Feromonas/metabolismo , Animais , Feminino , Proteínas de Insetos/genética , Lepidópteros/genética , Masculino , Feromônios/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Receptores de Feromonas/genética
12.
Pestic Biochem Physiol ; 156: 152-159, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31027575

RESUMO

Sex pheromone biosynthesis in moths relies on the activity of multiple enzymes, including Δ9 desaturase, which plays an important role in catalyzing desaturation at the Δ9 position of the carbon chain. However, the physiological function of moth Δ9 desaturase has not been elucidated in vivo. In this study, we used the CRISPR/Cas9 system to knockout the Δ9 desaturase gene (SlitDes11) of Spodoptera litura to analyze its role in sex pheromone biosynthesis. First, through the direct injection of SlitDes11-single guide RNA (sgRNA)/Cas9 messenger RNA into newly laid eggs, gene editing was induced in around 30% of eggs 24 h after injection and was induced in 20.8% of the resulting adult moths. Second, using a sibling-crossing strategy, insects with mutant SlitDes11 (bearing a premature stop codon) were selected, and homozygous mutants were obtained in the G5 generation. Third, pheromone gland extracts of adult female homozygous SlitDes11 mutants were analyzed using Gas chromatography (GC). The results showed that titers of all three ester sex pheromone components; Z9, E11-14:Ac, Z9,E12-14:Ac, and Z9-14:Ac; were reduced by 62.40%, 78.50%, and 72.50%, respectively. This study provides the first direct evidence for the role of SlitDes11 in sex pheromone biosynthesis in S. litura, and indicates the gene could be as potential target to disrupt sexual communication in S. litura for developing a new pollution-free insecticide.


Assuntos
Proteínas de Insetos/metabolismo , Atrativos Sexuais/metabolismo , Spodoptera/metabolismo , Estearoil-CoA Dessaturase/metabolismo , Sequência de Aminoácidos , Animais , Feminino , Mutação em Linhagem Germinativa , Proteínas de Insetos/química , Proteínas de Insetos/genética , Mariposas/metabolismo , Mutação/genética , RNA Mensageiro , Alinhamento de Sequência
13.
Mar Pollut Bull ; 141: 387-397, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30955748

RESUMO

To investigate the effects of mariculture on the sources, distribution and preservation of sedimentary organic carbon (SOC), sediments from an mariculture area in Ailian Bay, China, and a control area were analyzed for grain size composition, total organic carbon (TOC), total nitrogen (TN), carbon/nitrogen (C/N) ratio, and stable carbon and nitrogen isotopic composition (δ13C and δ15N). The sedimentary type of sediments in study area was clay silt. TOC, TN, C/N, δ13C, and δ15N ranged from 0.58 to 1.21%, 0.06-0.17%, 6.29-9.82, -23.20 to -18.50‰, and 6.17-7.38‰, respectively, and followed similar spatial patterns. TOC, TN and δ13C were higher in mariculture area than in control area. Biodeposit and kelp OC contributions greater of SOC in mariculture area than the control area (biodeposits: 20.10 ±â€¯4.84 to 6.2 ±â€¯1.3%; kelp: 15.3 ±â€¯6.63 to 5.2 ±â€¯0.84%). Overall, mariculture activities significantly influence the sources, distribution and preservation of SOC.


Assuntos
Aquicultura/métodos , Monitoramento Ambiental/métodos , Gastrópodes/crescimento & desenvolvimento , Sedimentos Geológicos/química , Kelp/crescimento & desenvolvimento , Poluentes Químicos da Água/análise , Animais , Baías/química , Carbono/análise , Ciclo do Carbono , Isótopos de Carbono/análise , China , Nitrogênio/análise , Isótopos de Nitrogênio/análise
14.
Artigo em Inglês | MEDLINE | ID: mdl-30861459

RESUMO

Acute heat stress is common in aquaculture and can affect diverse physiological processes in fish; however, different species of fish have various mechanisms for heat stress adaptation. In this study, we profiled the transcriptome responses of the Atlantic salmon (Salmo salar) to heat stress at 23 °C for 6 or 24 h, compared with that of fish at a normal temperature of 13 °C. The liver was selected as the target tissue for this analysis. A total of 243 and 88 genes were differentially expressed after 6 and 24 h of heat stress, respectively. Of these, only 22 were common to both time points, and most of these common genes were molecular chaperones such as heat shock cognate 71 kDa protein and heat shock protein 90-alpha. Genes such as activating transcription factor 6, calreticulin, protein disulfide isomerase A3, and protein kinase R-like endoplasmic reticulum kinase-eukaryotic initiation factor 2-alpha were only up-regulated after 6 h of heat stress; most of these genes are involved in the endoplasmic reticulum stress pathway. Indeed, endoplasmic reticulum stress was identified at 6 h but not at 24 h, suggesting that stress response plays an important role in the adaptation of Atlantic salmon to acute heat stress. Other up-regulated genes at 6 h were related to the insulin and nucleotide oligomerization domain-like receptor signaling pathways, which directly eliminate misfolded proteins and sustain sugar and lipid homeostasis. At 24 h, heat stress influenced the expression of steroid and terpenoid backbone biosynthesis, which may influence the sexual development and differentiation of Atlantic salmon. Overall, our results elucidate the transcriptome mechanisms that contribute to short-term heat tolerance in the liver of Atlantic salmon.


Assuntos
Resposta ao Choque Térmico , Salmo salar/genética , Transcriptoma , Adaptação Fisiológica , Animais , Aquicultura , Proteínas de Peixes/genética , RNA-Seq , Salmo salar/fisiologia
15.
Insect Sci ; 26(3): 388-399, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29058383

RESUMO

Pheromone-binding proteins (PBPs) are thought to bind and transport sex pheromones onto the olfactory receptors on the dendrite membrane of olfactory neurons, and thus play a vital role in sex pheromone perception. However, the function of PBPs has rarely been demonstrated in vivo. In this study, two PBPs (PBP1 and PBP3) of Chilo suppressalis, one of the most notorious pyralid pests, were in vivo functionally characterized using insects with the PBP gene knocked out by the CRISPR/Cas9 system. First, through direct injection of PBP-single guide RNA (sgRNA)/Cas9 messenger RNA into newly laid eggs, a high rate of target-gene editing (checked with polled eggs) was induced at 24 h after injection, 21.3% for PBP1-sgRNA injected eggs and 19.5% for PBP3-sgRNA injected eggs. Second, by an in-crossing strategy, insects with mutant PBP1 or PBP3 (both with a premature stop codon) were screened, and homozygous mutants were obtained in the G3 generation. Third, the mutant insects were measured for electroantennogram (EAG) response to female sex pheromones. As a result, both PBP mutant males displayed significant reduction in EAG response, and this reduction in PBP1 mutants was higher than that in PBP3 mutants, indicating a more important role of PBP1. Finally, the relative importance of two PBPs and the possible off target effect induced by sgRNA-injection are discussed. Taken together, our study provides a deeper insight into the function of and interaction between different PBP genes in sex pheromone perception of C. suppressalis, as well as a valuable reference in methodology for gene functional study in other genes and other moth species.


Assuntos
Antenas de Artrópodes/fisiologia , Proteínas de Insetos/fisiologia , Mariposas/fisiologia , Atrativos Sexuais/metabolismo , Animais , Sequência de Bases , Sistemas CRISPR-Cas , Feminino , Homozigoto , Masculino , Mutação
16.
Ying Yong Sheng Tai Xue Bao ; 29(9): 3102-3110, 2018 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-30411588

RESUMO

Rainbow trout (Oncorhynchus mykiss) is a cold-water fish species with optimal temperature of 12-18 ℃. Temperature stress is a common issue in commercial culture of the Salmonid fish in summer. Both maple trout and steelhead trout are rainbow trout breeding species with good quality. The purpose of this study was to explore the impact of acute temperature stress on antioxidant responses of two kinds of rainbow trout. The juvenile maple trout was diploid, and the juvenile steelhead trout was triploid. The fishes were exposed to four different temperature treatments: 13, 17, 21, and 25 ℃, and hepatic samples were collected at 0, 1, 6, and 12 h. After acute heat stress, the fish were transferred to the tank with optimal temperature (13 ℃) and hepatic samples were collected after 1, 12, 24, and 48 h. The biomarkers, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), lipid peroxidation (LPO), malondialdehyde (MDA), and heat shock protein 70 kDa (HSP70) were measured. Results showed that the activities of SOD, CAT, and GPx in both maple trout and steelhead trout in 17 ℃ treatment had no significant increase after acute temperature stress. The SOD activities of maple trout and steelhead trout in 21 ℃ treatment significantly increased in response to acute temperature stress, but the SOD activity of maple trout returned to normal during the recovery process. The activities of SOD, CAT, and GPx for both species in 25 ℃ treatment were significantly increased after acute temperature stress, which returned to normal for 24 h recovery. The amount of HSP70 produced by maple trout at 17, 21, and 25 ℃ treatments was significantly higher than that at 13 ℃ treatment, while that of steelhead trout was significantly higher for the 21 and 25 ℃ treatments than that at 13 ℃ treatment. A variety of antioxidant parameters were analyzed by integrated biomarker response (IBR) values. Results showed that the antioxidant response of maple trout was significantly higher than that of steelhead trout in 17 ℃ and 21 ℃ treatments, but significantly lower than steelhead trout in 25 ℃ treatment. Such a result indicated that the antioxidant responses of different ploidy rainbow trouts were different under acute stress at different temperatures.


Assuntos
Antioxidantes/metabolismo , Oncorhynchus mykiss/fisiologia , Estresse Fisiológico/fisiologia , Animais , Melhoramento Vegetal , Ploidias , Temperatura
17.
J Insect Physiol ; 111: 25-31, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30336148

RESUMO

Chrysoperla sinica is an important natural predator of many notorious agricultural pests. Understanding its olfactory mechanism can help enhance the effectiveness of C. sinica in biological control. In the present study, we investigated the tissue expression patterns of 12 odorant-binding protein (OBP) genes from C. sinica (CsinOBPs). The results of quantitative real-time polymerase chain reaction (qPCR) showed that CsinOBP1, CsinOBP2, CsinOBP3, CsinOBP4, CsinOBP6, CsinOBP7, CsinOBP9, CsinOBP10, and CsinOBP12 were predominantly expressed in the antennae of both sexes, indicating their roles in olfaction. Additionally, the qPCR analysis revealed that the 12 CsinOBP genes had distinct expression patterns, while the motif-pattern investigation suggested that the OBPs had different ligands. The ligand-binding assay showed that CsinOBP1 and CsinOBP10 had broader binding spectra than did the other OBPs. Thus, CsinOBP1 was able to bind not only plant volatiles (such as farnesol, cis-3-hexenyl hexanoate, geranylacetone, ß-ionone, 2-tridecanone, and trans-nerolidol) but also the aphid alarm pheromone (E)-ß-farnesene. On the other hand, CsinOBP2 and CsinOBP6 exhibited relatively narrow binding spectra, only binding ethyl benzoate. The study also identified several compounds that can potentially be used to develop slow-release agents attracting C. sinica and to improve search strategies for insect pest control.


Assuntos
Proteínas de Insetos/genética , Insetos/genética , Feromônios/metabolismo , Receptores Odorantes/genética , Compostos Orgânicos Voláteis/metabolismo , Sequência de Aminoácidos , Animais , Feminino , Perfilação da Expressão Gênica , Proteínas de Insetos/metabolismo , Masculino , Comportamento Predatório , Ligação Proteica , Receptores Odorantes/metabolismo
18.
J Insect Sci ; 18(5)2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30260453

RESUMO

The high sensitivity of the olfactory system is essential for feeding and oviposition in moth insects, and some chemosensory proteins (CSPs) are thought to play roles in this system by binding and carrying hydrophobic odorants across the aqueous sensillar lymph. In this study, to identify the olfactory CSPs from a repertoire of 21 CSP members in the notorious rice pest Chilo suppressalis (Walker) (Lepidoptera: Pyralidae), tissue expression patterns were firstly examined by quantitative real-time polymerase chain reaction (qPCR). It showed that CSP2 was antennae specific and seven more CSPs (CSP1, 3, 4, 6, 15, 16, and 17) were antennae biased in expression, suggesting their olfactory roles; while other CSPs were multiple-tissue expressed and non-antennae biased, suggesting other functions for these genes. To further determine the ligand binding specificity, three putative olfactory genes (CSP1-3) were expressed in Escherichia coli cells, and binding affinity of these three recombinant CSP proteins were measured for 35 plant volatiles by the ligand binding assays. CSP1 and CSP2 exhibited high binding affinities (Ki ≤ 10.00 µM) for four (2-tridecanone, benzaldehyde, laurinaldehyde and 2-pentadecanone) and two (2-heptanol and (+)-cedrol) host plant volatiles, respectively; the three CSPs also showed moderate binding affinity (Ki = 10.01-20.00 µM) for 16 plant volatiles. Our study suggests that the three CSPs play essential roles in the perception of host plant volatiles, providing bases for the elucidation of olfactory mechanisms in this important pyralid pest.


Assuntos
Antenas de Artrópodes/fisiologia , Proteínas de Insetos/metabolismo , Mariposas/fisiologia , Percepção Olfatória , Compostos Orgânicos Voláteis/metabolismo , Animais , Feminino , Perfilação da Expressão Gênica , Masculino , Mariposas/genética , Reação em Cadeia da Polimerase em Tempo Real , Fatores Sexuais
19.
J Chem Ecol ; 44(10): 886-893, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30094705

RESUMO

Orthaga achatina (Lepidoptera: Pyralidae) is the most serious pest in south China of camphor trees, Cinnamomum camphora (L.) Presl, an important urban tree species. Gas chromatography-electroantennographic detection (GC-EAD) of the sex pheromone of O. achatina showed three EAD-active components. Coupled gas chromatography/mass spectrometry analyses identified these as (Z)-11-hexadecenol (Z11-16:OH), (Z)-11-hexadecenyl acetate (Z11-16:OAc), and (3Z,6Z,9Z,12Z,15Z)-tricosapentaene (Z3,Z6,Z9,Z12,Z15-23:H). In field tests using different combinations of the three compounds, male moths were attracted to a mixture of Z11-16:OAc and Z3,Z6,Z9,Z12,Z15-23:H, but less attracted to other blends. Further field tests with different ratios of the two compounds determined the optimal ratio of the binary blend as 500:250. The addition of Z11-16:OH to Z11-16:OAc, or to the binary mixture of Z11-16: OAc and the pentaene did not yield higher catches. This shows that O. achatina uses a mixture of Type I and Type II sex pheromone components. Orthaga achatina is the third Pyraloidea species found to utilize Z3,Z6,Z9,Z12,Z15-23:H as a sex pheromone component.


Assuntos
Lepidópteros/química , Lepidópteros/efeitos dos fármacos , Atrativos Sexuais/química , Atrativos Sexuais/farmacologia , Animais , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Masculino , Comportamento Sexual Animal/efeitos dos fármacos
20.
Insect Biochem Mol Biol ; 99: 37-53, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29800678

RESUMO

The functions of the Ionotropic Receptor (IR) family have been well studied in Drosophila melanogaster, but only limited information is available in Lepidoptera. Here, we conducted a large-scale genome-wide analysis of the IR gene repertoire in 13 moths and 16 butterflies. Combining a homology-based approach and manual efforts, totally 996 IR candidates are identified including 31 pseudogenes and 825 full-length sequences, representing the most current comprehensive annotation in lepidopteran species. The phylogeny, expression and sequence characteristics classify Lepidoptera IRs into three sub-families: antennal IRs (A-IRs), divergent IRs (D-IRs) and Lepidoptera-specific IRs (LS-IRs), which is distinct from the case of Drosophila IRs. In comparison to LS-IRs and D-IRs, A-IRs members share a higher degree of protein identity and are distinguished into 16 orthologous groups in the phylogeny, showing conservation of gene structure. Analysis of selective forces on 27 orthologous groups reveals that these lepidopteran IRs have evolved under strong purifying selection (dN/dS≪1). Most notably, lineage-specific gene duplications that contribute primarily to gene number variations across Lepidoptera not only exist in D-IRs, but are present in the two other sub-families including members of IR41a, 76b, 87a, 100a and 100b. Expression profiling analysis reveals that over 80% (21/26) of Helicoverpa armigera A-IRs are expressed more highly in antennae of adults or larvae than other tissues, consistent with its proposed function in olfaction. However, some are also detected in taste organs like proboscises and legs. These results suggest that some A-IRs in H. armigera likely bear a dual function with their involvement in olfaction and gustation. Results from mating experiments show that two HarmIRs (IR1.2 and IR75d) expression is significantly up-regulated in antennae of mated female moths. However, no expression difference is observed between unmated female and male adults, suggesting an association with female host-searching behaviors. Our current study has greatly extended the IR gene repertoire resource in Lepidoptera, and more importantly, identifies potential IR candidates for olfactory, gustatory and oviposition behaviors in the cotton bollworm.


Assuntos
Regulação da Expressão Gênica/fisiologia , Genoma de Inseto/fisiologia , Estudo de Associação Genômica Ampla , Proteínas de Insetos , Lepidópteros , Receptores Ionotrópicos de Glutamato , Animais , Drosophila melanogaster , Proteínas de Insetos/biossíntese , Proteínas de Insetos/genética , Lepidópteros/genética , Lepidópteros/metabolismo , Receptores Ionotrópicos de Glutamato/biossíntese , Receptores Ionotrópicos de Glutamato/genética
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