Objective To sequence transcriptomes of unfed female Haemaphysalis longicornis using IlluminaHiSeq high-throughput technology.

Methods The data on sequences the transcriptomes were spliced and assembled, and the obtained sequences were analyzed with functional annotation, functional classification, metabolic pathway analysis and simple repeated sequence markers using bioinformatics methods.

Results A total of 181 246 184 clean reads data were obtained and 107 428 unigene sequences were obtained after assembly, with an average length of 1 246.29. All unigene sequences were aligned with the Nr, Nt, Pfam, KOG, Swiss-prot, KEGG, GO databases using BLAST software. Compared with the Nr database, the long-horned blood scorpion gene sequence has a high homology (55.3%) with that of Ixodes scapularis. According to the annotation of the GO database, the functions of the all unigene sequences were divided into 3 categories (biological process, cellular component and molecular function) covering 56 functional groups; based on to the annotations of the KOG database, all the unigene sequences were assigned into 25 categories; while, according to the analysis of the KEGG database, there are 32 groups of genes involved in metabolic pathways and a major part of them (12.13%) are involved in signal transduction. A total of 45 863 simple sequence repeats (SSRs) were identified with SSR locus search. Single nucleotide polymorphism (SNP) analysis indicated that the number of SNPs for base transition was 195 369 and that for base transversion was 96 780.

Conclusion The analysis on transcriptomes of unfed female Haemaphysalis longicornis lays a foundation for subsequent researches on gene expression and expression of the tick.