关键词: 冈比亚按蚊, 性别决定基因, doublesex, 显性致死昆虫施放技术, 序列分析, 表达谱

Abstract: 【Aim】 Doublesex (dsx) is a key gene involved in the sex determination system, which controls sex determination in the germ line and soma of insects. This study aims to obtain the full-length cDNA sequence of  dsx  from major malaria mosquito  Anopheles gambiae , to reveal the sex-specific differences in splicing patterns of dsx pre-mRNA, and to determine the expression profiles of  dsx  in different developmental stages. 【Methods】 The full-length cDNA of doublesex (Angdsx) were obtained from A. gambiae using RT-PCR and RACE methods. The motif prediction, multiple alignments of amino acid sequences and-phylogenetic analysis were conducted by corresponding bioinformatics softwares. RT-PCR analysis was performed to analyze its sex-specific and development-specific expression profiles. 【Results】 The full-length cDNA sequences of Angdsx  were cloned from female and male adults of A. gambiae, and named Angdsx^M (GenBank accession no. KM978938) and Angdsx^F (GenBank accession no. KM978937), respectively. Angdsx  covers an 80 kb genome region on chromosome 2R. Angdsx^F and Angdsx^M are 4 874 nt and 3 183 nt in length, encoding 265 and 633 amino acids, respectively. Besides the conserved motifs including TRA/TRA-2 binding site, dsx  repeat elements (dsx REs), arginine-serine rich protein, purine-rich enhancer and RNA-binding proteins target sequences, the GT repeat motifs were also indentified in Angdsx by meme program. Compared with Angdsx^M, Angdsx^F contains an extra female specific exon. RT-qPCR analysis displayed that the expression level of Angdsx^M was higher in 0-2 h  embryo and then declined, but increased from 12-24 h embryo again, while that of Angdsx^F raised from 6-8 h. 【Conclusion】 The full-length Angdsx gene was isolated and identified from A. gambiae, which shows conservation of functional domains and sex-specific splicing. This study contributes to understanding the sex differentiation in mosquitoes and may facilitate the application of transgenic mosquitoes based release of insects carrying a dominant lethal (RIDL) technology on vector control.

Key words: Anonpheles gambiae, sex-determining gene, doublesex, release of insects carrying a dominant lethal (RIDL), sequence analysis, expression profile