Identification of candidate chemosensory genes in Mythimna separata by transcriptomic analysis

Lixiao Du,Xincheng Zhao,Xiangzhi Liang,Xiwu Gao,Guirong Wang,Yang Liu

doi:10.1186/s12864-018-4898-0

Abstract

BackgroundThe oriental armyworm, Mythimna separata, is an economically important and common Lepidopteran pest of cereal crops. Chemoreception plays a key role in insect life, such as foraging, oviposition site selection, and mating partners. To better understand the chemosensory mechanisms in M. separata, transcriptomic analysis of antennae, labial palps, and proboscises were conducted using next-generation sequencing technology to identify members of the major chemosensory related genes.ResultsIn this study, 62 putative odorant receptors (OR), 20 ionotropic receptors (IR), 16 gustatory receptors (GR), 38 odorant binding proteins (OBP), 26 chemosensory proteins (CSP), and 2 sensory neuron membrane proteins (SNMP) were identified in M. separata by bioinformatics analysis. Phylogenetic analysis of these candidate proteins was performed. Differentially expressed genes (DEGs) analysis was used to determine the expressions of all candidate chemosensory genes and then the expression profiles of the three families of receptor genes were confirmed by real-time quantitative RT-PCR (qPCR).ConclusionsThe important genes for chemoreception have now been identified in M. separata. This study will provide valuable information for further functional studies of chemoreception mechanisms in this important agricultural pest.

Highlights

The oriental armyworm, Mythimna separata, is an economically important and common Lepidopteran pest of cereal crops
Assemblies led to the generation of 73,342, 71,552, 56,263, and 64,136 unigenes separately for female antenna, male antenna, labial palp, and proboscis
Expression levels of all 62 candidate odorant receptors (OR) were successfully detected in quantitative RT-PCR (qPCR) analysis (Fig. 7). These results indicated that all candidate ORs were antennae enriched, except for MsepOR26 and MespOR54, which were highly expressed in proboscises

Summary

Introduction

The oriental armyworm, Mythimna separata, is an economically important and common Lepidopteran pest of cereal crops. Insects live in environments where they are constantly surrounded by various chemical signals, including olfactory and taste. Perception of these chemical signals is crucial for insects, because they need to detect and distinguish these signals and perform corresponding behaviors such as feeding, mating, oviposition, or escaping [1]. At least three large and divergent receptor families (including odorant receptors (OR), ionotropic receptors (IR), and gustatory receptors (GR)), and three nonreceptor gene families (including odorant binding proteins (OBP), chemosensory proteins (CSP), and sensory neuron membrane proteins (SNMP)), are involved in the process of chemosensory reception [3,4,5,6,7,8,9,10,11,12]

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Discussion

Conclusion