Abstract: 【Aim】 The objective of this study is to establish the transcriptome database of adult tissues of the pine sawyer beetle, Monochamus alternatus, carrying and without carrying the pine wood nematode, Bursaphelenchus xylophilus, and to reveal the overall expression characteristics of M. alternatus in response to pine wood nematode. 【Methods】 The transcriptomes of epidermis, trachea and fat body of M. alternatus adults carrying and without carrying B. xylophilus were sequenced using the Illumina HiSeq^TM 2000 platform, the transcriptome data were de novo assembled using Trinity software, and gene annotation was conducted by using the NCBI database. The differentially expressed genes in M. alternatus adults carrying and without carrying B. xylophilus were screened by DEG-Seq, and the up-regulated genes were subjected to GO and KEGG metabolic pathway enrichment analysis. The expression levels of some differentially expressed genes including ENV, CDK1, HSP70-C, HSP70, HSP75, DUO, PABPN1 and IGFP genes were verified by real-time quantitative PCR (RT-qPCR). 【Results】 After sequencing and filtering, a total of 55 059 unigenes were obtained with an average length of 1 536 bp. A total of 24 354 unigenes were annotated using BLASTX searches against the databases, of which 4 022 unigenes were assigned in GO database and 6 098 unigenes were assigned in the KEGG database. The enrichment analysis of GO and KEGG showed that the main differentially expressed genes in the trachea of M. alternatus adults carrying B. xylophilus are related with pressure regulation, tissue and DNA repair, and hormone response. The RT-qPCR analysis showed that the expression levels of CDK1, HSP70, HSP75, DUO, PABPN1, and IGFP genes were significantly higher in the trachea of M. alternatus carrying pine wood nematodes than in the trachea of M. alternatus without carrying pine wood nematodes. 【Conclusion】 This study preliminarily clarified the overall expression pattern of the transcriptome of M. alternatus carrying B. xylophilus, providing a foundation for further study of the gene function of M. alternatus and the stress response of M. alternatus to B. xylophilus.

Key words: Monochamus alternatus; Bursaphelenchus xylophilus, transcriptome, gene annotation, GO, KEGG