关键词: 花椒窄吉丁, 转录组, 高通量测序, 基因注释, 生物信息学

Abstract: 【Aim】 To establish the transcriptome database of the Agrilus zanthoxylumi, and to obtain its genomic data. 【Methods】 The transcriptome of the different tissues (antennae, head, thorax, abdomen, leg, wing) of A. zanthoxylumi adults was sequenced using an Illumina NovaSeq 6000 platform, and the unigene sequences were compared with the homologous sequences in public databases by BLAST. Chemoreception-related genes were screened out by BLAST homology search, and their nucleotide sequences were compared with those of other reported chemoreception-related genes of Coleoptera insects for phylogenetic analysis. The expression levels of these genes in different tissues of A.zanthoxylumi adults were analyzed based on the RPKM value. 【Results】 After sequencing and sequence splicing, a total of 80 320 genes and 169 398 contigs were obtained. The G+C proportions of contigs and unigenes were 37.63% and 39.18%, respectively, and the average length of contigs and the average length of unigenes were 1 084.33 and 828.75 bp, respectively. There were 37 374 unigenes with a length distribution mainly in 200-400 bp, accounting for 46.53% of the total unigenes. Origin species distribution of similar genes with unigenes of A. zanthoxylumi annotated in the NR database was Tribolium castaneum (26.80%), Mus musculus (13.87%), Oryctes borbonicus (5.26%), Dendroctonus ponderosae (4.10%), Lasius niger (2.36%), and other species (47.61%). There were 27 488 unigenes aligned to the GO database, which can be divided into three functional categories including molecular function, cellular component and biological process in a total of 59 processes. According to the gene annotation against the  KOG database, these unigenes can be divided into 25 categories. The most annotated functional category was the common function (4 666 unigenes), while the least annotated was cell movement-related (only 40 unigenes). When 80 320 unigenes were mapped to the KEGG database, 21 104 unigenes were grouped into 35 metabolic pathways, accounting for 26.27% of the total. The most annotated metabolic pathway was the transcription pathway (2 037 unigenes). By gene annotation against the NR database, we found eight odorant receptor (OR) genes, seven ionotropic receptor (IR) genes and six gustatory receptor (GR) genes. Tissue expression profiles showed that the three kinds of chemoreception-related genes (OR, IR and GR genes) had significantly higher expression levels in the antennae than in other tissues of adults, and the expression level of AzanOR1 in the antennae showed the most significant difference between female and male, while the expression levels of the three kinds of chemoreception-related genes in the legs of adults showed no difference between female and male. 【Conclusion】 This study obtained the transcriptome data of A. zanthoxylumi. The results provide a molecular foundation for further studying the gene function in A. zanthoxylumi.

Key words: Agrilus zanthoxylumi, transcriptome, HiSeq, gene annotation, bioinformatics