title: De Novo Assembly and Characterization of the Transcriptome of Grasshopper Shirakiacris shirakii.
abstract: BACKGROUND
  The grasshopper Shirakiacris shirakii is an important agricultural pest and feeds mainly on gramineous plants, thereby causing economic damage to a wide range of crops. However, genomic information on this species is extremely limited thus far, and transcriptome data relevant to insecticide resistance and pest control are also not available.
  
  
  METHODS
  The transcriptome of S. shirakii was sequenced using the Illumina HiSeq platform, and we de novo assembled the transcriptome.
  
  
  RESULTS
  Its sequencing produced a total of 105,408,878 clean reads, and the de novo assembly revealed 74,657 unigenes with an average length of 680 bp and N50 of 1057 bp. A total of 28,173 unigenes were annotated for the NCBI non-redundant protein sequences (Nr), NCBI non-redundant nucleotide sequences (Nt), a manually-annotated and reviewed protein sequence database (Swiss-Prot), Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. Based on the Nr annotation results, we manually identified 79 unigenes encoding cytochrome P450 monooxygenases (P450s), 36 unigenes encoding carboxylesterases (CarEs) and 36 unigenes encoding glutathione S-transferases (GSTs) in S. shirakii. Core RNAi components relevant to miroRNA, siRNA and piRNA pathways, including Pasha, Loquacious, Argonaute-1, Argonaute-2, Argonaute-3, Zucchini, Aubergine, enhanced RNAi-1 and Piwi, were expressed in S. shirakii. We also identified five unigenes that were homologous to the Sid-1 gene. In addition, the analysis of differential gene expressions revealed that a total of 19,764 unigenes were up-regulated and 4185 unigenes were down-regulated in larvae. In total, we predicted 7504 simple sequence repeats (SSRs) from 74,657 unigenes.
  
  
  CONCLUSIONS
  The comprehensive de novo transcriptomic data of S. shirakii will offer a series of valuable molecular resources for better studying insecticide resistance, RNAi and molecular marker discovery in the transcriptome.
authors.affiliation: College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China. qiuzhongying11@126.com.
authors.forename: Zhongying
authors.initials: Z
authors.lastname: Qiu
authors.affiliation: College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China. liufei@snsy.edu.cn.|College of Life Sciences and Food Engineering, Shaanxi Xueqian Normal University, Xi'an 710061, China. liufei@snsy.edu.cn.
authors.forename: Fei
authors.initials: F
authors.lastname: Liu
authors.affiliation: Key Laboratory for Space Bioscience &amp; Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China. luhuimeng@nwpu.edu.cn.
authors.forename: Huimeng
authors.initials: H
authors.lastname: Lu
authors.affiliation: College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China. yuanhao@snnu.edu.cn.
authors.forename: Hao
authors.initials: H
authors.lastname: Yuan
authors.affiliation: College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China. shengkezhangqin@126.com.
authors.forename: Qin
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China. yuanh@snnu.edu.cn.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Huang
mesh_terms: D000818:Animals; D019295:Computational Biology; D020869:Gene Expression Profiling; D017343:Genes, Plant / Q000235:genetics*; D006110:Grasshoppers / Q000235:genetics*; D059014:High-Throughput Nucleotide Sequencing; D007814:Larva / Q000235:genetics*; D058977:Molecular Sequence Annotation; D010802:Phylogeny; D060888:Real-Time Polymerase Chain Reaction; D059467:Transcriptome / Q000235:genetics*
keywords: RNAi; Shirakiacris shirakii; differentially-expressed unigenes (DEUs); insecticide resistance; transcriptome