title: De novo assembly and analysis of midgut transcriptome of Haemaphysalis flava and identification of genes involved in blood digestion, feeding and defending from pathogens.
abstract: Bioactive components in the midgut of ticks play a key role in tick blood digestion, feeding and pathogen transmission. The study of protein and gene targets in midgut provides opportunities to explore novel tick control strategies. Only a few nucleotide sequences are available in public databases for Haemaphysalis flava, an important disease vector for humans and animals. Knowledge of the process of blood digestion by the ticks and protein expression in the digestive tract is limited. Here, we utilize high-throughput sequencing to characterize the midgut transcriptome of fully engorged (FE, average length of 10mm) and partially engorged (PE, average length of 5mm) female H. flava. 6.8GB and 8.3GB of high-quality sequence data were obtained using Illumina sequencing technology. 54,357,490 and 66,116,050 reads were finally assembled into 76,556 unigenes with mean length of 704bp. The transcripts involved in blood meal digestion were classified into eight large categories, including peptidase inhibitor, peptidase (serine-, metallo-, cysteine-, aspartic-peptidase), phospholipase, carbohydrate digestion/hydrolases, lipid binding, immunity-related proteins, iron/heme metabolism and secreted proteins. A total of 5508 differentially expressed genes (DEGs) were identified between FE and PE. To confirm the DEG results, ten genes involved in blood digestion, feeding and defending from pathogens, were validated using qPCR. Our results not only contribute to better understanding of the changes in midgut transcript expression during different blood feeding stages, but also provide a valuable resource for identifying targets for future tick control studies.
authors.affiliation: College of Veterinary Medicine, Hunan Agricultural University, Changsha 410128, Hunan Province, PR China; College of Life Sciences and Resource Environment, Yichun University, Yichun 336000, Jiangxi Province, PR China.
authors.forename: Xing-Li
authors.initials: XL
authors.lastname: Xu
authors.affiliation: College of Veterinary Medicine, Hunan Agricultural University, Changsha 410128, Hunan Province, PR China. Electronic address: hn5368@163.com.
authors.forename: Tian-Yin
authors.initials: TY
authors.lastname: Cheng
authors.affiliation: College of Life Sciences and Resource Environment, Yichun University, Yichun 336000, Jiangxi Province, PR China.
authors.forename: Hu
authors.initials: H
authors.lastname: Yang
authors.affiliation: College of Veterinary Medicine, Hunan Agricultural University, Changsha 410128, Hunan Province, PR China.
authors.forename: Zhi-Hui
authors.initials: ZH
authors.lastname: Liao
mesh_terms: D000818:Animals; D019295:Computational Biology; D005260:Female; D041981:Gastrointestinal Tract / Q000378:metabolism*; D020869:Gene Expression Profiling; D063990:Gene Ontology; D054884:Host-Pathogen Interactions; D026863:Ixodidae / Q000235:genetics*; D018895:Microsatellite Repeats; D058977:Molecular Sequence Annotation; D016366:Open Reading Frames; D017422:Sequence Analysis, DNA; D059467:Transcriptome
keywords: Haemaphysalis flava; Midgut; RNA-Seq; Transcriptome