Identification of odorant binding proteins and chemosensory proteins in Microplitis mediator as well as functional characterization of chemosensory protein 3
Identification of odorant binding proteins and chemosensory proteins in Microplitis mediator as well as functional characterization of chemosensory protein 3
Yong Peng 0 1
Shan-Ning Wang 1
Ke-Ming Li 1
Jing-Tao Liu 1
Yao Zheng 1
Shuang Shan 1
Ye-Qing Yang 0 1
Rui-Jun Li 0 1
Yong-Jun Zhang 1
Yu-Yuan Guo 1
0 College of Plant Protection, Agricultural University of Hebei , Baoding , China , 2 State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences , Beijing , China , 3 Institute of Banana and Plantain, Chinese Academy of Tropical Agricultural Sciences , Haikou , China , 4 College of Plant Protection, China Agricultural University , Beijing , China
1 Editor: Patrizia Falabella, Universita degli Studi della Basilicata , ITALY
Odorant binding proteins (OBPs) and chemosensory proteins (CSPs) play important roles in transporting semiochemicals through the sensillar lymph to olfactory receptors in insect antennae. In the present study, twenty OBPs and three CSPs were identified from the antennal transcriptome of Microplitis mediator. Ten OBPs (MmedOBP11±20) and two CSPs (MmedCSP2±3) were newly identified. The expression patterns of these new genes in olfactory and non-olfactory tissues were investigated by real-time quantitative PCR (qPCR) measurement. The results indicated that MmedOBP14, MmedOBP18, MmedCSP2 and MmedCSP3 were primarily expressed in antennae suggesting potential olfactory roles in M. mediator. However, other genes including MmedOBP11±13, 15±17, 19±20 appeared to be expressed at higher levels in body parts than in antennae. Focusing on the functional characterization of MmedCSP3, immunocytochemistry and fluorescent competitive binding assays were conducted indoors. It was found that MmedCSP3 was specifically located in the sensillum lymph of olfactory sensilla basiconca type 2. The recombinant MmedCSP3 could bind several types of host insects odors and plant volatiles. Interestingly, three sex pheromone components of Noctuidae insects, cis-11-hexadecenyl aldehyde (Z11-16: Ald), cis-11-hexadecanol (Z11-16: OH), and trans-11-tetradecenyl acetate (E11-14: Ac), showed high binding affinities (Ki = 17.24±18.77 μM). The MmedCSP3 may be involved in locating host insects. Our data provide a base for further investigating the physiological roles of OBPs and CSPs in M. mediator, and extend the function of MmedCSP3 in chemoreception of M. mediator.
Data Availability Statement: All relevant data are
available from the NCBI database. Specific
accession numbers are included in Table 2.
study design, data collection and analysis, decision
to publish, or preparation of the manuscript.
In insects, behaviors of host identification, mating-partners, and locating oviposition sites are
regulated largely by volatile chemical cues [
]. These odor molecules are usually perceived
by chemosensory sensilla located on their antennae . In insect olfaction model, odorants
enter the chemosensory sensilla through cuticular pores, dissolved in the sensillum lymph and
are captured by soluble carrier proteins, then activate sensory neurons [
]. Two major
classes of soluble proteins, odorant binding proteins (OBPs) and chemosensory proteins (CSPs)
play essential roles in transferring semiochemicals to the membrane-bonded receptors, and
may contribute to the activation of olfactory receptor neurons [
OBPs and CSPs were synthesized in non-neuronal support cells and secreted in the lymph
of chemosensilla at extraordinarily high concentrations [
]. Both OBPs and CSPs are small
(12±18 kDa) and soluble proteins which have capacities to bind reversibly small molecules [
]. OBPs were usually classified in different type depend on the motif of conserved cysteines,
and subdivide as typical OBPs, ªPlus-Cº OBPs, ªMinus-Cº OBPs, Dimer OBPs and Atypical
OBPs. Normal OBP include pheromone binding proteins (PBPs), general odorant binding
proteins (GOBPs) and antennal specific proteins (ASPs) or antennal-binding protein x (ABPx)
]. The first OBP was identified from Antheraea polyphemus and named ApolPBP1 [
Since then lots of OBPs and CSPs were identified and characterized in insect species [
Generally, most of OBPs are considered to be antenna-specific, whereas CSPs are more widely
distributed in different tissues of the insect body suggesting their multi-roles [15±17].
Microplitis mediator (Hymenoptera: Braconidae) is a polyphagous solitary larval
endoparasitoid that parasitizes approximately 40 species of Lepidoptera insects [
]. Several odor carrier
proteins including ten OBPs (MmdeOBP1±10) and one CSP (MmedCSP1) of M. mediator
were identified in our previous work [
]. The binding characteristics of these proteins
were also investigated by using fluorophore displacement assays [
]. However, some plant
volatiles, such as the (Z)-3-hexenyl acetate and (E)-2-hexenal, which could elicit
electrophysiological and behavioral responses of M. mediator showed no any binding affinity to above
mentioned MmedOBPs and MmedCSPs [
]. Thus, we suspected that there may be more
OBPs and CSPs unexplored in the antennae of M. mediator, which could bind more potential
semiochemicals. Encouragingly, the development of new sequencing technology provides a
strong support for the discovery of these genes.
In the current study, ten OBPs (MmedOBP11–20) and two CSPs (MmedCSP2–3) were
newly identified from the antennal transcriptome of M. mediator. The tissue- and sex- specific
expression profile was investigated by using quantitative real-time PCR (qPCR). Focusing on
the functional characterization of MmedCSP3, immunocytochemistry and fluorescent
competitive binding assays were performed indoors. Our results will provide a theoretical basis for
further investigating the physiological roles of OBPs and CSPs in M. mediator.
Materials and methods
A colony of M. mediator was obtained from the Institute of Plant Protection, Hebei Academy
of Agriculture and Forestry, China. Emerged adult parasitoids were fed with a 10% honey
solution in a growth chamber under the conditions of 28 ± 1ÊC, 75% relative humidity, and a 16: 8
(Light: Dark) photoperiod [
]. Female antennae, male antennae, heads (without antennae),
thoraxes, abdomens, legs and wings from two to three days old adult wasps were excised and
immediately frozen in liquid nitrogen, then stored at ±80ÊC before qPCR analysis.
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Total RNA extraction
Total RNA was extracted from different tissue samples by using Trizol reagent (Invitrogen
Carlsbad, CA, USA). The integrity of extracted RNA was checked by using 1.2% agarose gel
electrophoresis, and quantified using a ND-2000 spectrophotometer (NanoDrop, Wilmington,
DE, USA) at OD260 nm. The total RNA was treated with RQ1 RNase-Free DNase (Promega,
Madison, USA) at 37ÊC for 30 min to remove residual DNA. The cDNAs were synthesized
using the Fast Quant RT Kit (TianGen, Beijing, China).
Identification of OBPs and CSPs
The tBLASTn program was utilized with available sequences of OBPs and CSPs from
Hymenoptera species as ªqueryº sequences to identify candidate unigenes that encode OBPs and
CSPs in M. mediator [
]. All candidate transcripts were manually checked by using BLASTx
program of the NCBI website (http://blast.ncbi.nlm.nih.gov/Blast.cgi) [
primers were designed with the Beacon Designer 7 (PREMIER Bio-soft International) to
amplify the sequences of MmedOBP11–20 and MmedCSP2–3 (Table 1). Each reaction (25 μl
volume) containing 200 ng of cDNA from different tissues was used as a template. The cycling
parameters were: 95ÊC for 3 min; with 35 cycles as follows: 94ÊC for 45 sec, 58ÊC for 1 min,
72ÊC for 1 min; and a final extension step of 10 min at 72ÊC. The PCR product was gel-purified
and sub-cloned into the pEasy-T3 vector (TransGen, Beijing, China) and then sequencing
validation was performed.
The putative N-terminal signal peptides of OBPs and CSPs were predicted using the SignalP
4.0 server (http://www.cbs.dtu.dk/services/SignalP/). The open reading frames (ORFs) and the
associated amino acid sequences were determined by using GeneDoc 2.7.0 software. The
phylogenetic tree for OBP and CSP was constructed based on MmedOBP/CSP sequences and
orthologues in other Hymenoptera species [15, 27±29]. Amino acid sequences were aligned
using the program Clustal X 2.0 [
]. A neighbor-joining tree was constructed using the
MEGA 5.0 program [
] with a p-distance model and a pairwise deletion of gaps.
Bootstrapping was performed by the re-sampling amino acid positions of 1000 replicates.
The relative transcript abundance of MmedOBP and MmedCSP genes in different tissue
samples were evaluated by using qPCR measurement on an ABI Prism 7500 Fast Detection System
(Applied Biosystems, Carlsbad, CA). The reference gene β-actin (GenBank accession number:
KC193266) of M. mediator was used as the endogenous control to normalize the target gene
expression and correct for any sample-to-sample variation. The primers (Table 1) of the target
and reference genes were designed by Primer 3.0 program. The specificity of each primer set
was validated by melt-curve analysis, and the efficiency was calculated by analyzing standard
curves with a five-fold cDNA dilution series. Each qPCR reaction was conducted in a 20 μl
mixture containing 10 μl of 2 × SuperReal PreMix Plus (TianGen, Beijing, China), 0.6 μl of
each primer (10 μM), 0.4 μl of 50 × Rox Reference Dye, 1 μl of sample cDNA, 7.4 μl of
sterilized H2O. The qPCR cycling parameters consisted of 95ÊC for 15 min, followed by 40 cycles of
95ÊC for 10 sec and 60ÊC for 30 sec, and melt curves stages at 95ÊC for 15 sec, 60ÊC for 1 min,
and 95ÊC for 15 sec. The experiments for the test samples, endogenous control and negative
control were performed in triplicate to ensure reproducibility. Relative quantification was
performed using the comparative 2-ΔΔCt method [
]. All of the data were normalized to
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endogenous β-actin levels from the same tissue samples. The cycle threshold (CT) values of
OBPs and CSPs in different tissues are listed in S1 Table.
Expression and purification of recombinant MmedCSP3
MmedCSP3 was PCR-amplified using gene-specific primers (Table 1). The sample cDNA of
the antennae was used as the template. The PCR product was first cloned into a pEASY-T3
Vector (Takara, Dalian, China) and then excised and cloned into an expression vector
pET30a (+) for expression in prokaryotic BL21 (DE3) cells (Takara, Dalian, China). The
transformation of the strain with pET-30a (+) / MmedCSP3 was incubated in 500 mL of LB medium
with 100 μg / ml kanamycin at 37ÊC. When the OD of the culture reached 0.4±0.6, the protein
was induced with 1 mM isopropylthio-β-galactoside (IPTG) at 16ÊC and vibrated for 16 h at
200 rpm. The cultures were harvested by centrifugation at 12000 × g for 25 min at 4ÊC. The
supernatant was obtained by sonication, purified by Ni ion affinity chromatography (AÈ KTA
avant 25, GE Healthcare, USA). Soon after the His-tag was removed with recombinant
enterokinase (Novoprotein, Shanghai, China), followed by a second purification mentioned above. A
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15% sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis was
conducted to check the size and purity of recombinant MmedCSP3.
Western blot analysis
Polyclonal antiserum against recombinant MmedCSP3 was obtained by injecting robust adult
rabbits subcutaneously and intramuscularly with the highly purified recombinant MmedCSP3
proteins. The protein was emulsified with an equal volume of Freund's complete adjuvant
(Sigma, St. Louis, MO, USA) for the first injection (500 μg of recombinant protein) and
incomplete adjuvant for the three additional injections (300 μg each time). The interval
between each injection was approximately half a month, and rabbit blood was collected seven
days after the last injection and centrifuged at 6000 rpm for 20 min. The serum was further
purified using a MAb Trap kit (GE Healthcare, Milwaukee, WI, USA) following the
manufacturer's instructions. The rabbits were maintained in large cages at room temperature, and all
of the operations were performed according to ethical guidelines to minimize the pain and
discomfort of the animals.
The purified recombinant MmedCSP3 were separated by 15% SDS-PAGE and then
transferred to a polyvinylidene fluoride (Millipore, Carrigtwohill, Ireland) membrane.
Subsequently, the membrane was blocked with 5% skimmed milk in phosphate-buffered saline
(PBS) containing 0.05% Tween-20 (PBST) overnight at 4ÊC. After washing thrice with PBST
(10 min each time), the blocked membrane was incubated with the purified rabbit
antiMmedCSP3 antiserum (dilution 1: 5,000) for 1 h at room temperature. After washings thrice
with PBST, the membrane was incubated with goat anti-rabbit IgG horseradish peroxidase
(HRP) conjugate and HRP-streptavidin complex (Promega, Madison, WI, USA) at a dilution
of 1: 10,000 for 1 h. The membrane was then incubated with the Easy-See Western Blot kit
(TransGen Biotech, Beijing, China), and exposed by Image-Quant LAS 4000 mini (GE
Healthcare Bio-Sciences AB, Uppsala, Sweden).
Male or female antennae of two- or three-day-old adult wasps were fixed in a mixture of
paraformaldehyde (4%) and glutaraldehyde (2%) in 0.1 M PBS (pH 7.4) at room temperature for
24 h, dehydrated in an ethanol series, and embedded in LR white resin (Taab, Aldermaston,
Berks, UK) for polymerization at 60ÊC. Ultrathin sections (60±80 nm) were cut using a
diamond knife on a Reichert Ultracut ultramicrotome (Reichert Company, Vienna, Austria). For
immunocytochemical assay, the grids were subsequently floated in 25 μl droplets of PBSG
(PBS containing 50 mM glycine) and PBGT (PBS containing 0.2% gelatin, 1% bovine serum
albumin, and 0.02% Tween-20) and incubated with purified rabbit anti-MmedCSP3 antiserum
(dilution 1: 2,000) at 4ÊC overnight. After washing six times with PBGT, the sections were
incubated with secondary antibody (anti-rabbit IgG) coupled with 10 nm colloidal gold
granules (Sigma, St. Louis, MO, USA) at a dilution of 1: 20 at room temperature for 90 min. Before
being observed with a Hitachi H-7500 TEM (Hitachi Ltd., Tokyo, Japan), the sections were
subjected to optional silver intensification for 15 min and stained with 2% uranyl acetate to
increase the contrast. The serum supernatant from an un-injected healthy rabbit at the same
dilution rate acted as the negative control. Three male and female adult antennae were
respectively used in immunocytochemical assays.
Fluorescence binding test
The binding abilities of MmedCSP3 to 102 candidate chemicals were measured on a
fluorescence spectrometer (F-380, Tianjin, China) in a 1 cm light path quartz cuvette with 10 nm slits
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for both excitation and emission. The 4, 4'-dianilino-1,1'-binaphthyl-5,5'-sulfonic acid
(bisANS, Sigma, Riedstr, Steinheim, Germany) as fluorescent probe was excited at 365 nm and
emission spectra were recorded from 435 to 620 nm. The bis-ANS and all compounds were
dissolved in HPLC purity-grade methanol with a concentration of 1 mM. 2 μM solution of the
protein in 50 mM Tris-HCl (pH 7.4) was titrated with aliquots of bis-ANS prepared in advance
to final concentrations of 2±16 μM to measure the affinity of bis-ANS to the protein. The
affinities of other ligands were measured in competitive binding assays with the protein and
bisANS at 2 μM in the presence of each competitor at 2±40 μM.
The fluorescence intensities at the maximum fluorescence emission between 435 to 620 nm
were plotted against the free ligand concentration to determine the binding constants. The
bound chemical was evaluated based on its fluorescence intensity with the assumption that
the protein was 100% active with a stoichiometry of 1: 1 (protein: ligand) saturation. The
binding curves were linearized using a Scatchard plot, and the dissociation constants of the
competitors were calculated from the corresponding IC50 values based on the following equation:
Ki = [IC50] / (1 + [bis-ANS] / Kbis-ANS), where [bis-ANS] is the free concentration of bis-ANS
and Kbis-ANS is the dissociation constant of the complex protein / bis-ANS [
Data analysis was performed using SPSS Statistics 18.0 software (SPSS Inc., Chicago, IL, USA).
ANOVA and Tukey HSD new multiple range test (P < 0.05) were used to compare the
expression of each target gene among various tissues.
Identification of OBPs and CSPs
In the present study, a total of twenty MmedOBPs and three MmedCSPs were identified from
antennal transcriptome of M. mediator. The BLASTx results indicated that ten OBPs and
two CSPs were newly identified (Table 2), which were named as MmedOBP11–20 and
MmedCSP2–3, respectively, based on our previous work [
]. Besides MmedOBP12,
MmedOBP14 and MmedOBP20, all other proteins had intact ORFs and encoded polypeptides
Best BLASTx hit
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Fig 1. Sequence alignment of all identified OBPs and CSPs in M. mediator. A: Sequence alignment of
OBPs, six conserved cysteine residues are marked in black; B: Sequence alignment of CSPs, four conserved
cysteine residues are marked in black. Predicted signal peptides are boxed in the figure.
with signal peptide (Fig 1A). All the twenty MmedOBPs had six conserved cysteine residues,
while three MmedCSPs had four conserved cysteine residues (Fig 1B). After sequencing, all
sequences of newly identified MmedOPBs and MmedCSPs were deposited in GenBank with
the accession numbers listed in Table 2. The phylogenetic tree showed that OBPs and CSPs
almost clustered in two distinct groups. Fourteen MmedOBPs are clustered in four
speciesspecific clades, whereas six MmedOBPs were significantly divergent from each other and
clustered together with their orthologs in other species (Fig 2). Each of the MmedCSPs was
clustered together with the CSPs from other Hymenoptera species.
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Fig 2. Phylogenetic tree of OBPs and CSPs from Hymenoptera species. Mmed (red): M. mediator; Ccun (purple): Chouioia cunea; Ssp (green):
Sclerodermus sp.; Amel (blue): Apis mellifera.
Tissue expression profiles of MmedOBPs and MmedCSPs
The qPCR results showed that only two OBPs, MmedOBP14 and MmedOBP18, were highly
expressed in antennae (Fig 3). MmedOBP14 was specific expressed in antennae of male wasps,
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Fig 3. qPCR analysis of MmedOBPs and MmedCSPs expression in different tissues. The error bars represent
standard error and the different small letters above each bar indicate significant differences in transcript abundances
(P < 0.05).
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while MmedOBP18 had slightly high expressions in antennae of female adults. Interestingly,
some MmedOBPs were mainly expressed in non-olfactory tissues. MmedOBP15 was mainly
expressed in the heads of wasps, MmedOBP19 was primarily expressed in the legs rather than
in the antennae, MmedOBP20 was only detected in the abdomen, MmedOBP12 and
MmedOBP13 were primarily expressed in the heads and thoraxes; while three OBPs (MmedOBP11,
16, 17) were highly enriched in the thoraxes. Two MmedCSPs were mainly expressed in the
antennae of adult wasps. The transcript level of MmedCSP2 was higher in females than in
males, while MmedCSP3 showed high expressions in antennae of both male and female wasps.
Location of MmedCSP3 in antennae
Focusing on MmedCSP3, the anti-MmedCSP3 antiserums were used to mark the cellular
localization of MmedCSP3 in antennal sensilla of M. mediator. Western blot analysis showed
that the antibody could specifically bind to the purified recombinant MmedCSP3 (Fig 4).
Fig 4. SDS-PAGE and western blot analysis of recombinant MmedCSP3. M: Molecular weight marker; 1:
Non-induced pET-30a (+) / MmedCSP3; 2: Induced pET-30a (+) / MmedCSP3; 3: pET-30a (+) / MmedCSP3
supernatant; 4: pET-30a (+) / MmedCSP3 pellet; 5: Purified MmedCSP3 with His-tag; 6: Purified MmedCSP3
without His-tag; 7: Western blot analysis of MmedCSP3.
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Fig 5. Immunocytochemical localization of MmedCSP3 in sensilla on female antennae. (A): The
sensilla basiconica type 2 was labeled strongly, whereas the sensilla placodea were not labeled. (B): The
sensillum lymph in the sensilla basiconica type 2 was strong labeled. sp, s. placodea; st, s. trichodea; c,
cavity; d, dendrites; p, pore; w, sensillum wall.
Immunolocalization results indicated that MmedCSP3 could be labeled in the sensilla
basiconca type 2 (Fig 5A and 5B). The gold granules were concentrated at the sensillum lymph in
the sensillum hair lumen and the cavity below the hair base. However, there was no
MmedCSP3 labeled in the sensilla placodea. Immunolocalization data of MmedCSP3 in
antennal sensilla of males were consistent with that in female antennae.
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Fluorescence binding assay
The relative affinities of the recombinant MmedCSP3 with 102 candidate compounds were
evaluated by fluorescence binding assays (Table 3). The candidate compounds were selected
from known plant volatiles and some specific host insect odorants. The dissociation constant
of the MmedCSP3 / bis-ANS complexes was 1.75 ± 0.42 μM (Fig 6A). Among the tested
compounds, only nine chemicals showed certain affinities with MmedCSP3. The selected
plant volatiles, (3E, 7E)-4, 8, 12-trimethyltrideca-1, 3, 7, 11-tetraene (TMTT), 1,
1-dimethyl-2[4-(5-nitrofuran-2-yl)-1,3-thiazol-2-yl] hydrazine (DMNT), ethyl butyrate, and medthyl
salicylate exhibited relatively weak binding abilities with MmedCSP3, and the Ki values ranged
from 26.79 μM to 39.22 μM (Fig 6B). Interestingly, octadecenoic acid, palmitic acid, three sex
pheromone components of Noctuidae insects, cis-11-hexadecenyl aldehyde (Z11-16: Ald),
cis11-hexadecanol (Z11-16: OH), and trans-11-tetradecenyl acetate (E11-14: Ac), displayed high
binding abilities, and the Ki values ranged from 17.24 μM to 22.20 μM (Fig 6C and 6D).
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Fig 6. Binding characteristic of selected ligands to MmedCSP3. (A) Binding curve and relative Scatchard plot of bis-ANS to MmedCSP3. (B)
Competitive binding curves of four selected plant volatiles to MmedCSP3 (C) Competitive binding curves of three sex pheromone components to
MmedCSP3. (D) Competitive binding curved of two fatty acids to MmedCSP3.
In the present study, we obtained 20 OBPs and 3 CSPs from the antennal transcriptome of
M. mediator, among them 10 OBPs and 2 CSPs were newly reported. There are 52 OBPs and 4
CSPs identified in Drosophila melanogaster [
], 45 OBPs and 16 CSPs in Bombyx mori [
while Apis mellifera has 21 OBPs and 6 CSPs [
], C. cunea has 25 OBPs and 11 CSPs .
The total number of OBPs and CSPs in M. mediator is smaller than in D. melanogaster and B.
mori, but similar to those in A. mellifera and C. cunea. We suspected that there was less OBPs
and CSPs in Hymenoptera insects. Of course, some potential OBPs and CSPs may not able to
be identified in M. mediator due to low expressions level in the antennae or specific expression
in other tissues.
Both MmedOBP1–10 and MmedCSP1 have been reported highly abundant or specific in
the antennae of M. mediator [
]. In the current study, MmedOBP14, MmedOBP18 and
MmedCSP2–3 were abundantly expressed in the antennae of wasps. Antennae-enriched odor
carrier proteins of M. mediator play important roles in detecting mates and locating suitable
hosts. In insects, most OBPs are specifically or mainly expressed in chemosensory organs,
whereas some OBPs are also expressed in non-chemosensory organs suggesting their potential
non-olfactory functions. For example, MmedOBP20 was highly expressed in abdomen, which
might be involved in the physiological process of reproduction. Generally, CSPs are considered
to be widely distributed throughout the body of insects. However, antenna-specific CSPs were
also reported in the Adelphocoris lineolatus [
]. MmedCSP2–3 were mainly expressed in
antennae of both sexes suggesting important roles in chemoreception of M. mediator.
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There are six types of sensilla including sensilla basiconica identified in antennae of M.
]. Sensilla basiconica are multiporous chemosensilla . MmedCSP3 had
high level in sensillar lymph of sensilla basiconica type 2 indicating its roles in olfactory
perception of M. mediator. In fluorescence competitive binding assays, MmedOBP3 showed
certain binding affinities with selected plant volatiles. TMTT and methyl salicylate are
components of herbivore induced plant volatiles (HIPVs), which are considered dependable cues for
foraging parasitoids [
]. Palmitic acid and octadecenoic acid are long-chain free fatty
acids, which are commonly found both in plants and insects . It was demonstrated that
female Cotesia glomerata could use fatty acids from host-damaged leaves to search host insects
]. MmedOBP3 of M. mediator may play important roles in detecting plant volatiles, and we
proposed that M. mediator could use plant volatiles or insect odors to locate hosts or sexual
partners. Two semiochemicals, Z11-16: Ald and Z11-16: OH are main sex pheromone
components of cotton bollworm [
], E11-14: Ac is a sex pheromone component of Spodoptera
litura . Interestingly, in the present study, MmedCSP3 displayed high binding affinities
with these three chemicals. It was reported that cotesia plutellae could be attracted by the sex
pheromones of its host, plutella xylostella [
]. MmedCSP3 may be involved in perception of
host insect sex pheromones. M. mediator could locate host insects by the detection of insect
sex pheromones. Therefore, MmedCSP3 may play important roles in chemoreception of M.
mediator. The MmedCSP3 could be used as a potential target to regulate the olfactory behavior
of parasitic wasps. However, gene editing and behavioral assays need to be further performed
to verify the roles of this protein.
S1 Table. The cycle threshold (CT) value of OBPs and CSPs in different tissues.
This manuscript has been edited by the native English-speaking experts of Elsevier Language
Conceptualization: Rui-Jun Li, Yong-Jun Zhang, Yu-Yuan Guo.
Data curation: Yong Peng, Shan-Ning Wang, Ke-Ming Li, Jing-Tao Liu, Yao Zheng, Shuang
Shan, Ye-Qing Yang, Rui-Jun Li, Yong-Jun Zhang.
Formal analysis: Yong Peng, Shan-Ning Wang, Yong-Jun Zhang.
Funding acquisition: Yong-Jun Zhang, Yu-Yuan Guo.
Investigation: Yong Peng, Shan-Ning Wang, Ke-Ming Li, Jing-Tao Liu, Yao Zheng, Shuang
Shan, Ye-Qing Yang.
Methodology: Shan-Ning Wang, Rui-Jun Li, Yong-Jun Zhang.
Project administration: Yong-Jun Zhang, Yu-Yuan Guo.
Resources: Yong Peng, Shan-Ning Wang, Rui-Jun Li.
Supervision: Rui-Jun Li, Yong-Jun Zhang, Yu-Yuan Guo.
Writing ± original draft: Yong Peng, Shan-Ning Wang, Yong-Jun Zhang.
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Writing ± review & editing: Yong Peng, Rui-Jun Li, Yong-Jun Zhang, Yu-Yuan Guo.
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