埃及伊蚊性别决定基因 Transformer 2 的鉴定与表达分析

Isolation and expression profiling of transformer 2 gene in Aedes aegypti

目的分离、鉴定和分析埃及伊蚊性别决定基因Transformer 2(Aaetra2)。方法通过生物信息学方法与分子生物学方法获得了Aaetra2基因的全长。通过与已知物种tra2的比较,分析Aaetra2的基因结构特点与分子进化特征,通过RT-PCR方法验证Aaetra2的时间与组织表达特点。结果分离并鉴定Aaetra2-α与Aaetra2-β两个基因,它们位于染色体不同部位,通过选择性启动子的剪切策略进行自我调控,转录多种mRNA。埃及伊蚊TRA2蛋白具有保守的RRM、RS1、RS2和linker功能结构域区。Aaetra2表达方式无时间特异性的,从卵持续性表达至成虫阶段,且无性别特异性表达与组织特异性表达。结论 Aaetra2具有保守的昆虫性别决定基因tra2的功能结构域与表达特征,对其深入研究将为其最终应结合释放携带显性致死基因的昆虫技术应用于蚊虫的防制提供理论依据。

Objective To isolate, identify and analyze the sex-determining gene Transformer 2 （Aaetra2） of the major vector mosquito Aedes aegypti. Methods tBLASTn program, RT-PCR and RACE methods were used to obtain the full-length cDNA of Aaetra2. Multiple alignments of nucleotide and amino acid sequences were conducted, and the different domains in tra2 protein were indentified. RT-PCR of the total RNA extracted from different tissue from the mosquitoes in different developmental stages was performed using specific primers. Results Two genes, namely Aaetra2-a and Aaetra2-~, were identified in different supercontig locations. The multi-transcripts were expressed by means of alternative promoters or terminators. The different domains in tra2 protein were defined as RS-rich N-terminal region, RNA recognition motif-RRM, 1Lr^ker region, and RS-rich C-terminal region. Both Aaetra2-a and Aaetra2-~ showed sustained expression throughout the developmental stages of Ae.aegypti, and in all the tissues without a sex specificity. Conclusion Aaetra2 gene has multiple isoforms and is mapped to multiple locations in the genome. Aaetra2 has conservative functional domains of the sex-determining gene tra2. For Ae.agypti, Aaetra2 shows the potential as a new target for release of insects carrying a dominant lethal （RIDL） technology based on transgenic mosquitoes.