Acta Entomologica Sinica ›› 2017, Vol. 60 ›› Issue (2): 136-147.doi: 10.16380/j.kcxb.2017.02.002

• RESEARCH PAPERS • Previous Articles     Next Articles

Genome-wide identification and characterization of genes of the chemosensory protein (CSP) family in Anopheles sinensis (Diptera: Culicidae)

MEI Ting, HE Zheng-Bo, WANG Xiao-Ting, WANG Ting-Ting, CHEN Bin*   

  1. (Chongqing Key Laboratory of Vector Insects, Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing 401331, China)
  • Online:2017-02-20 Published:2017-02-20

Abstract: 【Aim】 The study aims to identify the genes of the chemosensory protein (CSP) family in Anopheles sinensis whole-genome, to predict the characteristics of these CSP genes, and to investigate the phylogenetics and evolution of the CSPs in representative dipteran species. 【Methods】 We searched, identified and named the CSP genes in An. sinensisAn. gambiaeAedes aegypti and Culex quinquefasciatus genomes with Blast and HMM methods using CSP amino acid sequences downloaded from NCBI database as inquiry entry, analyzed the characteristics of the CSP genes in An. sinensis using bioinformatics methods, including the structure, location, splicing and Ka/Ks ratio of these genes, conservative domains and protein structures, and deduced the phylogeny of CSP genes using maximum likelihood (ML) method with MEGA software. 【Results】 The genomes of An. sinensisAn. gambiaeAe. aegypti and Cx. quinquefasciatus contain 8, 8, 43 and 27 CSP genes, respectively. The CSP genes identified in An. sinensis (AsCSPs) are all supported by full-length transcripts, encoding 116 (AsCSP7) to 335 (AsCSP5) amino acids. Out of them, seven AsCSPs are located on Scaffold 51 and AsCSP8 on Scaffold116. AsCSP1-AsCSP8 possess 3, 2, 1, 1, 1, 2, 1 and 2 splicing variants, respectively, and AsCSP3 shows the highest expression level with a FPKM value of 385.46. All AsCSPs each has a N-terminal signal peptide consisting of 17-37 amino acids, and contains 4 conserved cysteine sites (CYS68, CYS75, CYS94 and CYS97), which define two disulfide bonds (CYS68-CYS75 and CYS94-CYS97). Phylogenetic analysis results showed that eight CSP genes in four mosquito species are each grouped into a significant clade, and were named as CSP1-CSP8 group, respectively. Thirty-five and 18 CSP genes in Ae. aegypti and Cx. quinquefasciatus, respectively, are grouped into a special clade without homologous genes with Anopheles species, and was named as the Culicinae-specific group in this study. The Ka/Ks values of orthologous gene pairs between An. sinensis and An. gambiae were all less than 1, suggesting that the CSP gene family mainly experienced purifying selection during evolution. 【Conclusion】 The study provides an information frame of the CSP gene family in mosquito species, especially An. sinensis, and lays the foundation for further functional analysis of these genes.

Key words: Anopheles sinensis, chemosensory protein; genome-wide identification; bioinformatics; gene characteristics; phylogeny