Phylogenetic tree of the odorant receptor (Or) family in <i>S. endius</i>, <i>N. vitripennis</i> and <i>A. mellifera</i>.

<p>AmGrs are marked in orange, NvGrs are in blue and PvGrs are red.</p

Size distribution of the transcripts and CDSs.

<p>The blue and red bars indicate unigenes and CDS, respectively.</p

Transcriptomics and Identification of the Chemoreceptor Superfamily of the Pupal Parasitoid of the Oriental Fruit Fly, <i>Spalangia endius</i> Walker (Hymenoptera: Pteromalidae)

<div><p>Background</p><p>The oriental fruit fly, <i>Bactrocera dorsalis</i> Hendel, causes serious losses to fruit production and is one of the most economically important pests in many countries, including China, <i>Spalangia endius</i> Walker is a pupal parasitoid of various dipteran hosts, and may be considered a potentially important ectoparasitic pupal parasitoid of <i>B. dorsalis</i>. However, lack of genetic information on this organism is an obstacle to understanding the mechanisms behind its interaction with this host. Analysis of the <i>S. endius</i> transcriptome is essential to extend the resources of genetic information on this species and, to support studies on <i>S. endius</i> on the host <i>B. dorsalis</i>.</p><p>Methodology/Principal Findings</p><p>We performed <i>de novo</i> assembly RNA-seq of <i>S. endius</i>. We obtained nearly 10 Gbp of data using a HiSeq platform, and 36319 high-quality transcripts using Trinity software. A total of 22443 (61.79%) unigenes were aligned to homologous sequences in the jewel wasp and honeybee (<i>Apis florae</i>) protein set from public databases. A total of 10037 protein domains were identified in 7892 <i>S. endius</i> transcripts using HMMER3 software. We identified expression of six gustatory receptor and 21 odorant receptor genes in the sample, with only one gene having a high expression level in each family. The other genes had a low expression level, including two genes regulated by splicing. This result may be due to the wasps being kept under laboratory conditions. Additionally, a total of 3727 SSR markers were predicted, which could facilitate the identification of polymorphisms and functional genes within wasp populations.</p><p>Conclusion/Significance</p><p>This transcriptome greatly improves our genetic understanding of <i>S. endius</i> and provides a large number of gene sequences for further study.</p></div

Summary of annotations of <i>S. endius</i> transcripts.

<p>Summary of annotations of <i>S. endius</i> transcripts.</p

Summary of sequencing and assembly for <i>S. endius.</i>

<p>Summary of sequencing and assembly for <i>S. endius.</i></p

Summary of gene family classification among four species, <i>S. endius</i>, <i>N. vitripennis</i>, <i>A. florea</i> and <i>D. melanogaster</i>.

<p>Summary of gene family classification among four species, <i>S. endius</i>, <i>N. vitripennis</i>, <i>A. florea</i> and <i>D. melanogaster</i>.</p

Summary of top 15 domains predicted in <i>S. endius</i> transcripts.

<p>Summary of top 15 domains predicted in <i>S. endius</i> transcripts.</p