Identification of differentially expressed immunity‐related genes in Monochamus alternatus Hope (Coleoptera: Cerambycidae) larvae parasitized by Dastarcus helophoroides (Fairmaire) (Coleoptera: Bothrideridae)

Abstract

AbstractThe pine sawyer Monochamus alternatus Hope (Coleoptera: Cerambycidae) is a serious pest of several Pinus species, and the ectoparasitoid larvae of Dastarcus helophoroides (Fairmaire) (Coleoptera: Bothrideridae) is an important natural enemy of this pest. The transcriptome of M. alternatus larvae was sequenced using the Illumina platform and immunity‐related genes were specifically analyzed. De novo assembly resulted in the identification of 24 241 unigenes, with a mean length of 1122 bp, in unparasitized M. alternatus larvae and 23 807 unigenes, with a mean length of 1140 bp, for parasitized larvae. Removal of redundant unigenes resulted in 26 095 all‐unigenes, of which 16 959 (64.99%) showed clear homology with some of the known genes in the National Center for Biotechnology Information nr database. Parasitization had notable effects on the transcriptome profile of M. alternatus larvae. In all, 2702 genes were differentially expressed in M. alternatus larvae after parasitization, with 1491 (55.18%) upregulated and 1211 (44.82%) downregulated. Moreover, expression levels of immunity‐related genes in M. alternatus larvae were markedly altered in response to parasitization by D. helophoroides. In conclusion, the transcriptome profiling data, especially the discovered of immunity‐related genes, help illustrate the molecular mechanisms of parasitism between D. helophoroides and M. alternatus and provide new insights into developing immunity regulation‐mediated control methods of M. alternatus.