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Transcriptome and expression profiling analysis link patterns of gene expression to antennal responses in Spodoptera litura.

Feng B, Lin X, Zheng K, Qian K, Chang Y, Du Y - BMC Genomics (2015)

Bottom Line: The majority of olfactory genes showed sex-biased expression, usually male-biased in ORs.A link between OR gene expression and antennal responses to odors was evident, a third of the compounds tested evoking a sex-biased response, in every case also male-biased.Two candidate pheromone receptors, OR14 and OR23 were especially strongly expressed and male-biased and we suggest that these may respond to the two female sex pheromone components of S. litura, Z9E11-14:OAc and Z9E12-14:OAc, which evoked strongly male-biased EAG responses.

View Article: PubMed Central - PubMed

Affiliation: Institute of Health and Environmental Ecology, Wenzhou Medical University, University Town, Wenzhou, 325035, China. fb820529@aliyun.com.

ABSTRACT

Background: The study of olfaction is key to understanding the interaction of insects with their environment and provides opportunities to develop novel tactics for control of pest species. Recent developments in transcriptomic approaches enable the molecular basis of olfaction to be studied even in species with limited genomic information. Here we use transcriptome and expression profiling analysis to characterize the antennal transcriptome of the noctuid moth and polyphagous pest Spodoptera litura.

Results: We identify 74 candidate genes involved in odor detection and recognition, encoding 26 ORs, 21 OBPs, 18 CSPs and 9 IRs. We examine their expression levels in both sexes and seek evidence for their function by relating their expression with levels of EAG response in male and female antennae to 58 host and non-host plant volatiles and sex pheromone components. The majority of olfactory genes showed sex-biased expression, usually male-biased in ORs. A link between OR gene expression and antennal responses to odors was evident, a third of the compounds tested evoking a sex-biased response, in every case also male-biased. Two candidate pheromone receptors, OR14 and OR23 were especially strongly expressed and male-biased and we suggest that these may respond to the two female sex pheromone components of S. litura, Z9E11-14:OAc and Z9E12-14:OAc, which evoked strongly male-biased EAG responses.

Conclusions: Our results provide the molecular basis for elucidating the olfactory profile of moths and the sexual divergence of their behavior and could enable the targeting of particular genes, and behaviors for pest management.

No MeSH data available.


Related in: MedlinePlus

Expression levels of candidate IRs in maleand femaleS. lituraantennae measured in single-endRNA-seqence (A) and RT-qPCR (B). In single-endRNA-seqence, vertical axis means the log scale of RPKM value to10. The significant difference between female and male wasjustified by method of Audic and Claverie (1997) and indicatedby symbol “*” (FDR < 0.01 and P < 0.05). In RT-qPCR,vertical axis means log scale of female gene expression to 10.Female gene expression was calculated by the2-∆∆Cq algorithm with male ascontrol and GAPDH andUCCR as reference genes.The significant difference was ascertained by Students t test. Symbol “*” means thesignificant difference between female and male (P < 0.05).Error bars signify SD”.
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Fig7: Expression levels of candidate IRs in maleand femaleS. lituraantennae measured in single-endRNA-seqence (A) and RT-qPCR (B). In single-endRNA-seqence, vertical axis means the log scale of RPKM value to10. The significant difference between female and male wasjustified by method of Audic and Claverie (1997) and indicatedby symbol “*” (FDR < 0.01 and P < 0.05). In RT-qPCR,vertical axis means log scale of female gene expression to 10.Female gene expression was calculated by the2-∆∆Cq algorithm with male ascontrol and GAPDH andUCCR as reference genes.The significant difference was ascertained by Students t test. Symbol “*” means thesignificant difference between female and male (P < 0.05).Error bars signify SD”.

Mentions: By contrast with candidate pheromone receptors, the expressionlevels of candidate pheromone-binding protein (PBP) genes in antennae were veryhigh, the male expression of PBP1 being the highest expression of all olfactorygenes at 94161 RPKM (Figure 3A). Thesex-bias expression varied greatly between the three PBPs, being stronglymale-biased for PBP1 and female biased for PBP3 (Figure 3A). The levels of expression of other odorantbinding proteins in the antennae were extremely variable, with RPKM valuesranging from less than 50 to over 20,000 (Figure 5A). Five OBPs were shown to be more highly expressed infemale antennae and 3 OBPs to be more highly expressed in male antennae insingle-end RNA-Seq and RT-qPCR (Figure 5). However, the total number of male-biased OBPs were the sameas that of female (Figure 4). The rangeof expression levels of CSP genes in the antennae was as extreme as for OBPs,RPKM values ranging from less than 10 to almost 20,000 (Figure 6A). Twelve CSP genes showed sex differences intheir levels of antennal expression, 5 being more expressed in females and 7more expressed in males and sometimes these differences were marked(Figure 6). The expression levels ofIR genes were as low as those of ORs and the largest RPKM value was about 1000(Figure 7A). Of which, IGluR1 wasfemale biased and IR8a was male biased (Figure 7). Only the expression levels of 3 ORs, PBP2 and CSP5showed significant difference by using GAPDHand UCCR as reference genes.Figure 5


Transcriptome and expression profiling analysis link patterns of gene expression to antennal responses in Spodoptera litura.

Feng B, Lin X, Zheng K, Qian K, Chang Y, Du Y - BMC Genomics (2015)

Expression levels of candidate IRs in maleand femaleS. lituraantennae measured in single-endRNA-seqence (A) and RT-qPCR (B). In single-endRNA-seqence, vertical axis means the log scale of RPKM value to10. The significant difference between female and male wasjustified by method of Audic and Claverie (1997) and indicatedby symbol “*” (FDR < 0.01 and P < 0.05). In RT-qPCR,vertical axis means log scale of female gene expression to 10.Female gene expression was calculated by the2-∆∆Cq algorithm with male ascontrol and GAPDH andUCCR as reference genes.The significant difference was ascertained by Students t test. Symbol “*” means thesignificant difference between female and male (P < 0.05).Error bars signify SD”.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4502548&req=5

Fig7: Expression levels of candidate IRs in maleand femaleS. lituraantennae measured in single-endRNA-seqence (A) and RT-qPCR (B). In single-endRNA-seqence, vertical axis means the log scale of RPKM value to10. The significant difference between female and male wasjustified by method of Audic and Claverie (1997) and indicatedby symbol “*” (FDR < 0.01 and P < 0.05). In RT-qPCR,vertical axis means log scale of female gene expression to 10.Female gene expression was calculated by the2-∆∆Cq algorithm with male ascontrol and GAPDH andUCCR as reference genes.The significant difference was ascertained by Students t test. Symbol “*” means thesignificant difference between female and male (P < 0.05).Error bars signify SD”.
Mentions: By contrast with candidate pheromone receptors, the expressionlevels of candidate pheromone-binding protein (PBP) genes in antennae were veryhigh, the male expression of PBP1 being the highest expression of all olfactorygenes at 94161 RPKM (Figure 3A). Thesex-bias expression varied greatly between the three PBPs, being stronglymale-biased for PBP1 and female biased for PBP3 (Figure 3A). The levels of expression of other odorantbinding proteins in the antennae were extremely variable, with RPKM valuesranging from less than 50 to over 20,000 (Figure 5A). Five OBPs were shown to be more highly expressed infemale antennae and 3 OBPs to be more highly expressed in male antennae insingle-end RNA-Seq and RT-qPCR (Figure 5). However, the total number of male-biased OBPs were the sameas that of female (Figure 4). The rangeof expression levels of CSP genes in the antennae was as extreme as for OBPs,RPKM values ranging from less than 10 to almost 20,000 (Figure 6A). Twelve CSP genes showed sex differences intheir levels of antennal expression, 5 being more expressed in females and 7more expressed in males and sometimes these differences were marked(Figure 6). The expression levels ofIR genes were as low as those of ORs and the largest RPKM value was about 1000(Figure 7A). Of which, IGluR1 wasfemale biased and IR8a was male biased (Figure 7). Only the expression levels of 3 ORs, PBP2 and CSP5showed significant difference by using GAPDHand UCCR as reference genes.Figure 5

Bottom Line: The majority of olfactory genes showed sex-biased expression, usually male-biased in ORs.A link between OR gene expression and antennal responses to odors was evident, a third of the compounds tested evoking a sex-biased response, in every case also male-biased.Two candidate pheromone receptors, OR14 and OR23 were especially strongly expressed and male-biased and we suggest that these may respond to the two female sex pheromone components of S. litura, Z9E11-14:OAc and Z9E12-14:OAc, which evoked strongly male-biased EAG responses.

View Article: PubMed Central - PubMed

Affiliation: Institute of Health and Environmental Ecology, Wenzhou Medical University, University Town, Wenzhou, 325035, China. fb820529@aliyun.com.

ABSTRACT

Background: The study of olfaction is key to understanding the interaction of insects with their environment and provides opportunities to develop novel tactics for control of pest species. Recent developments in transcriptomic approaches enable the molecular basis of olfaction to be studied even in species with limited genomic information. Here we use transcriptome and expression profiling analysis to characterize the antennal transcriptome of the noctuid moth and polyphagous pest Spodoptera litura.

Results: We identify 74 candidate genes involved in odor detection and recognition, encoding 26 ORs, 21 OBPs, 18 CSPs and 9 IRs. We examine their expression levels in both sexes and seek evidence for their function by relating their expression with levels of EAG response in male and female antennae to 58 host and non-host plant volatiles and sex pheromone components. The majority of olfactory genes showed sex-biased expression, usually male-biased in ORs. A link between OR gene expression and antennal responses to odors was evident, a third of the compounds tested evoking a sex-biased response, in every case also male-biased. Two candidate pheromone receptors, OR14 and OR23 were especially strongly expressed and male-biased and we suggest that these may respond to the two female sex pheromone components of S. litura, Z9E11-14:OAc and Z9E12-14:OAc, which evoked strongly male-biased EAG responses.

Conclusions: Our results provide the molecular basis for elucidating the olfactory profile of moths and the sexual divergence of their behavior and could enable the targeting of particular genes, and behaviors for pest management.

No MeSH data available.


Related in: MedlinePlus