球孢白僵菌对蜱致病的关键基因研究

Ticks, as haematophagous ectoparasites of many mammal species, are second only to mosquitoes as vectors of disease-causing agents to humans, and they are vectors of various diseases in humans and other animals.Despite much research to develop efficient methods to mediate tick and tick-borne diseases in livestock facilities, the most prevalent means of control remains mass eradication of the tick population by chemical acaricides. The unlimited and indiscriminate use of acaricides has resulted in many problems, such as heritable resistance of ticks, drug residue and environmental pollution. Therefore, many studies focus on the alternative approaches, biology control of ticks, and the key issue is to select the high virulence strains and molecular remodeling. In the proposal, the transcriptomic profiles of high and low virulence strains of Beauveria bassiana will be sequenced and analysed by an integrated approach. The comparison of transcriptome data of the high and low virulence strains in performed to screen and differently expressed genes associated with pathogenicity to ticks. Finally, the relationship between gene and pathogenicity of B. bassiana to tick will be futher confirmed by real-time PCR, PCR-array and gene knockout techniques. Implementation of this project will be contribute to clarify pathogenic mechanism of B.bassiana for controlling B.microplus and molecular construction of high virulence strains.

蜱为寄生于家畜体表的外寄生虫，除直接危害外，还可传播原虫病和多种病毒、细菌类人兽共患病，是除蚊之外的第二大传播媒介。长期以来，人们主要采用化学药物进行防治，但随着人们对蜱耐药性和药物残留及环境污染等问题的关注，围绕天敌真菌开展的、蜱的生物防治研究日益受到国际学术界的关注，而真菌对蜱致病性形成的关键分子鉴定，是高致病性菌株分子重构的基础。本项目以球孢白僵菌为研究对象，以微小牛蜱为代表，通过对实验室内已获得的高致病及弱致病性菌株转录组测序与分析，筛选差异基因，采用实时荧光定量PCR及PCR-array进行验证后，针对关键差异基因构建基因敲除菌株，通过蜱的体外感染试验观察致病性变化，鉴定与致病性相关的关键分子，为阐明白僵菌对蜱的致病机制及高致病性菌株的分子构建奠定基础。