Analysis of the Antennal Transcriptome and Insights into Olfactory Genes in Hyphantria cunea (Drury)

Long-Wa Zhang,Yun-Qiu Yang,Shi-Chang Jiang,Jing Zhang,Tian-Tian Wang,De-Gui Ding,Ke Kang,Li-Ya Jiang,Long Sun,Chang-Chun Huang,Ya-Nan Zhang,Subhabrata Sanyal

doi:10.1371/journal.pone.0164729

Long-Wa Zhang, Yun-Qiu Yang + Show 10 more

Open Access

https://doi.org/10.1371/journal.pone.0164729

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Journal: PLOS ONE	Publication Date: Oct 14, 2016
Citations: 41	License type: CC BY 4.0

Affiliation: Anhui Agricultural University, Huaibei Normal University

Abstract

Hyphantria cunea (Drury) (Lepidoptera: Arctiidae) is an invasive insect pest which, in China, causes unprecedented damage and economic losses due to its extreme fecundity and wide host range, including forest and shade trees, and even crops. Compared to the better known lepidopteran species which use Type-I pheromones, little is known at the molecular level about the olfactory mechanisms of host location and mate choice in H. cunea, a species using Type-II lepidopteran pheromones. In the present study, the H. cunea antennal transcriptome was constructed by Illumina Hiseq 2500TM sequencing, with the aim of discovering olfaction-related genes. We obtained 64,020,776 clean reads, and 59,243 unigenes from the analysis of the transcriptome, and the putative gene functions were annotated using gene ontology (GO) annotation. We further identified 124 putative chemosensory unigenes based on homology searches and phylogenetic analysis, including 30 odorant binding proteins (OBPs), 17 chemosensory proteins (CSPs), 52 odorant receptors (ORs), 14 ionotropic receptors (IRs), nine gustatory receptors (GRs) and two sensory neuron membrane proteins (SNMPs). We also found many conserved motif patterns of OBPs and CSPs using a MEME system. Moreover, we systematically analyzed expression patterns of OBPs and CSPs based on reverse transcription PCR and quantitative real time PCR (RT-qPCR) with RNA extracted from different tissues and life stages of both sexes in H. cunea. The antennae-biased expression may provide a deeper further understanding of olfactory processing in H. cunea. The first ever identification of olfactory genes in H. cunea may provide new leads for control of this major pest.

Highlights

Olfaction plays a vital role in behaviors such as mating, foraging, and ovipositing for insects, especially Lepidoptera [1, 2]
After removing adaptors and low quality reads, 64,020,776 clean reads were acquired with a Q20 percentage of 96.03%, which were assembled into 78,131 transcripts with a mean length of 1123 bp and an N50 length of 2520 bp. 59,243 unigenes were selected from the above transcripts with a mean length of 829 bp and an N50 length of 1803 bp. 35,976 unigenes were longer than 300 bp which accounted for 60.73% of all unigenes (S1 Fig)
The functional annotation of unigenes was performed by a BLAST homology search against the protein databases. 15,242 (25.72%) unigenes were annotated in the Nr database

Summary

Introduction

Olfaction plays a vital role in behaviors such as mating, foraging, and ovipositing for insects, especially Lepidoptera [1, 2]. The peripheral olfactory proteins involved in the reception of odorants in insects include odorant binding proteins (OBPs), chemosensory proteins (CSPs), odorant receptors (ORs), ionotropic receptors (IRs), gustatory receptors (GRs), and sensory neuron membrane proteins (SNMPs) [4,5,6]. GRs, IRs are another two receptors, which participate in the chemreception. IRs were more recently identified as a novel chemoreceptor family which evolved from ionotropic glutamate receptors (iGluRs) [6, 11, 12]. SNMPs are belong to the CD36 membrane proteins family that are located on dendrites and are crucial for pheromone recognition [11, 13]

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