Nutrigenomics in Arma chinensis: Transcriptome Analysis of Arma chinensis Fed on Artificial Diet and Chinese Oak Silk Moth Antheraea pernyi Pupae

Deyu Zou,Chenxi Liu,Hongyin Chen,Mengqing Wang,Thomas A. Coudron,Lisheng Zhang,Zhanjiang Liu

doi:10.1371/journal.pone.0060881

Abstract

BackgroundThe insect predator, Arma chinensis, is capable of effectively controlling many pests, such as Colorado potato beetle, cotton bollworm, and mirid bugs. Our previous study demonstrated several life history parameters were diminished for A. chinensis reared on an artificial diet compared to a natural food source like the Chinese oak silk moth pupae. The molecular mechanisms underlying the nutritive impact of the artificial diet on A. chinensis health are unclear. So we utilized transcriptome information to better understand the impact of the artificial diet on A. chinensis at the molecular level.Methodology/Principal FindingsIllumina HiSeq2000 was used to sequence 4.79 and 4.70 Gb of the transcriptome from pupae-fed and artificial diet-fed A. chinensis libraries, respectively, and a de novo transcriptome assembly was performed (Trinity short read assembler). This resulted in 112,029 and 98,724 contigs, clustered into 54,083 and 54,169 unigenes for pupae-fed and diet-fed A. chinensis, respectively. Unigenes from each sample’s assembly underwent sequence splicing and redundancy removal to acquire non-redundant unigenes. We obtained 55,189 unigenes of A. chinensis, including 12,046 distinct clusters and 43,143 distinct singletons. Unigene sequences were aligned by BLASTx to nr, Swiss-Prot, KEGG and COG (E-value <10−5), and further aligned by BLASTn to nt (E-value <10−5), retrieving proteins of highest sequence similarity with the given unigenes along with their protein functional annotations. Totally, 22,964, 7,898, 18,069, 15,416, 8,066 and 5,341 unigenes were annotated in nr, nt, Swiss-Prot, KEGG, COG and GO, respectively. We compared gene expression variations and found thousands of genes were differentially expressed between pupae-fed and diet-fed A. chinensis.Conclusions/SignificanceOur study provides abundant genomic data and offers comprehensive sequence information for studying A. chinensis. Additionally, the physiological roles of the differentially expressed genes enable us to predict effects of some dietary ingredients and subsequently propose formulation improvements to artificial diets.

Highlights

Arma chinensis is a predaceous insect species that preys upon a large variety of species, and can effectively suppress agricultural and forest pests in the orders Lepidoptera, Coleoptera, Hymenoptera and Hemiptera [1,2,3,4,5,6,7,8]
Sequencing and Sequence Assembly After removal of adaptor sequences, ambiguous reads and lowquality reads (Q20,20), a total of 53,224,704 (SRA accession number SRR617645) and 52,244,538 (SRA accession number SRR618073) high-quality clean reads comprised of 4,790,223,360 nucleotides (4.79 Gb) and 4,702,008,420 nucleotides (4.70 Gb) from the Chinese oak silk moth pupae-fed (CY_1) and artificial diet-fed (AD_1) A. chinensis libraries were generated, respectively
Since the nutrition of the artificial diet increased longevity in A. chinensis, we looked at Drosophila data for insight on the expression pattern of genes found to affect longevity, as discovered by functional analysis from DAVID 6.7 bioinformatic resources [61] and GoToolbox [62]

Summary

Introduction

Arma chinensis is a predaceous insect species that preys upon a large variety of species, and can effectively suppress agricultural and forest pests in the orders Lepidoptera, Coleoptera, Hymenoptera and Hemiptera [1,2,3,4,5,6,7,8]. The release of A. chinensis in association with transgenic crops may be a sustainable biocontrol strategy to decrease dependence on insecticides. Mass rearing of biocontrol insects is important given the environmental, health and resistance issues associated with the use of chemical insecticides [13]. Fecundity and egg viability were lower for diet-fed A. chinensis compared to A. chinensis reared on pupae of the natural prey, the Chinese oak silk moth Antheraea pernyi. The insect predator, Arma chinensis, is capable of effectively controlling many pests, such as Colorado potato beetle, cotton bollworm, and mirid bugs. Our previous study demonstrated several life history parameters were diminished for A. chinensis reared on an artificial diet compared to a natural food source like the Chinese oak silk moth pupae. We utilized transcriptome information to better understand the impact of the artificial diet on A. chinensis at the molecular level

Methods

Results

Conclusion