title: De novo sequencing, assembly and analysis of salivary gland transcriptome of Haemaphysalis flava and identification of sialoprotein genes.
abstract: Saliva plays an important role in feeding and pathogen transmission, identification and analysis of tick salivary gland (SG) proteins is considered as a hot spot in anti-tick researching area. Herein, we present the first description of SG transcriptome of Haemaphysalis flava using next-generation sequencing (NGS). A total of over 143 million high-quality reads were assembled into 54,357 unigenes, of which 20,145 (37.06%) had significant similarities to proteins in the Swiss-Prot database. 13,513 annotated sequences were associated with GO terms. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that 14,280 unigenes were assigned to 279 KEGG pathways in total. Reads per kb per million reads (RPKM) analysis showed that there were 3035 down-regulated unigenes and 2260 up-regulated unigenes in the engorged ticks (ET) compared with the semi-engorged one (SET). Several important genes are associated with blood feeding and ingestion as secreted salivary proteins, concluding cysteine, longipain, 4D8, calreticulin, metalloproteases, serine protease inhibitor, enolase, heat shock protein and AV422 in SG, were identified. The qRT-PCR results confirmed that patterns of these genes (except for the longipain gene) expression were consistent with RNA-seq results. This de novo assembly of SG transcriptome of H. flava not only provides more chance for screening and cloning functional genes, but also forms a solid basis for further insight into the changes of salivary proteins during blood-feeding.
authors.affiliation: College of Veterinary Medicine, Hunan Agricultural University, Changsha 410128, PR China; College of Life Sciences and Resource Environment, Jiangxi Yichun University, Jiangxi, Yichun 336000, PR China.
authors.forename: Xing-Li
authors.initials: XL
authors.lastname: Xu
authors.affiliation: College of Veterinary Medicine, Hunan Agricultural University, Changsha 410128, 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, Jiangxi Yichun University, Jiangxi, Yichun 336000, PR China.
authors.forename: Hu
authors.initials: H
authors.lastname: Yang
authors.affiliation: College of Veterinary Medicine, Hunan Agricultural University, Changsha 410128, PR China.
authors.forename: Fen
authors.initials: F
authors.lastname: Yan
authors.affiliation: College of Veterinary Medicine, Hunan Agricultural University, Changsha 410128, PR China.
authors.forename: Ya
authors.initials: Y
authors.lastname: Yang
mesh_terms: D000818:Animals; D015723:Gene Library; D005796:Genes / Q000235:genetics*; D026863:Ixodidae / Q000235:genetics*; D016366:Open Reading Frames / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D012469:Salivary Glands / Q000378:metabolism*; D012795:Sialoglycoproteins / Q000235:genetics*; D059467:Transcriptome / Q000235:genetics*
chemical_list: D012795:Sialoglycoproteins
keywords: Haemaphysalis flava; High-throughput annotation; Salivary glands; Transcriptomes