阿拉善双峰驼MHC-DRB基因的多态性与其阴道蝇蛆病抗性的相关研究

Vaginal myiasis has become Inner Mongolia Alxan Bactrian camel principal harm disease. Its epidemic period was from May to October and in its high incidence area of prevalence, infestation rates was high up to 44.9% and the mortality rate was 33.3%, and its has been brought about huge economic loss to camel industry. The Effective period of drug therapy to the disease was Short-term (1 week) and its easy recurring again. So far,there has not been a good way to control the disease. Major histocompatibility complex ( MHC ) is the main component of the vertebrate immune system, and resistance to many diseases (including parasites ),immune response and production performance are closely correlated with it, especially in resistance to diseases, the MHC plays an important role. Making the phenomena of Bactrian camel to the vaginal myiasis has non susceptibility and susceptibility as a breakthrough point,then using of PCR-SSCP, PCR-RFIP and other methods to study of the MHC-DRB gene polymorphism in Bactrian camel. Through Making a statistical analysis and difference test between the MHC-DRB loci in different units of type with resistance to vaginal myiasis and susceptibility, looking for a genetic loci associate with resistance to vaginal myiasis, then screening molecular markers which associated with resistance to vaginal myiasis, and for the prevention and cure of vaginal myiasis in camel and provide a scientific data for the cultivation of new Bactrian camel lines for the resistance to vaginal myiasis.

阴道蝇蛆病已成为内蒙古阿拉善双峰驼首要危害疾病。该病在5-10月间流行，在其高发区，发病率高达44.9%，死亡率为33.3%，给养驼业带来巨大的经济损失。药物治疗见效期短（1周）反复发作，迄今为止还没有一个好的方法防治该病。主要组织相容性复合体（Major Histocompability Complex, MHC）是脊椎动物免疫系统的主要组成部分，与许多疾病（含寄生虫）的抗性、免疫应答以及生产性能都有着密切的联系，尤其在抵抗疾病方面起着重要作用。本课题以双峰驼阴道蝇蛆病具有易感和非易感性现象为切入点，利用PCR-SSCP,PCR-RFIP等方法对双峰驼MHC-DRB基因多态性进行研究。通过对MHC-DRB基因座不同单位型与该病的抗性和易感性之间进行研究，寻找具有抗阴道蝇蛆病相关的遗传位点，筛选出抗该病相关的分子标记，为骆驼阴道蝇蛆病的防治以及新品系的培育提供科学依据。

阴道蝇蛆病是阿拉善双峰驼主要危害疾病。该病发病率高、死亡率高，无长效药物治疗，反复发作，迄今为止还未找到理想的防治方法，给养驼业带来巨大的经济损失。主要组织相容性复合体（Major Histocompability Complex, MHC）是脊椎动物免疫系统的主要组成部分，与许多疾病（含寄生虫）的抗性、免疫应答以及生产性能都有着密切的联系，尤其在抵抗疾病方面起着重要作用。本项目在前期研究的基础上以双峰驼阴道蝇蛆病具有易感和非易感性现象为切入点，首先对阿拉善双峰驼MHC基因做了定位以及基因注释；再利用PCR-SSCP,PCR-RFIP等方法对双峰驼MHC-DRB基因多态性进行研究；围绕阴道黏膜免疫对阴道壁结构、阴道菌群多样性的微生态体系进行研究；同时对易感和非易感个体免疫性状进行比较研究；对黑须污蝇蝇蛆的各阶段生活史和形态结构做了鉴定和描述；最后对寄生蝇蛆的不同时期幼虫和成虫进行测序分析，筛选了一些相关基因进行研究。主要研究结果如下：. 课题组将阿拉善双峰驼MHC基因定位在了20号染色体短臂上的三条scaffolds，即NW_011511766.1（全长4.1M）、NW_011515227.1（全长1.2M）和NW_011514613.1（全长15K），注释到24个MHC基因，其中Ⅰ类基因1个，Ⅱ类10个, Ⅲ类基因13个；检测了双峰驼DRB基因外显子2的DNA序列和氨基酸序列以及等位基因的种类结果表明双峰驼MHC-DRB基因外显子2具有丰富的多态性；将患蝇蛆病驼和健康驼等位基因频率和基因型频率进行统计分析发现等位基因A在健康驼中的数量高于患蝇蛆病驼，等位基因B在患蝇蛆病驼中的数量高于健康驼，基因型AA和AB可能与蝇蛆病的抗性相关，基因型BB可能与蝇蛆病的易感性相关；从血常规和全血涂片，获得了白细胞、中性粒细胞、单核细胞、淋巴细胞、红细胞、血小板和血红蛋白含量等指标，血细胞数量的变化表明双峰驼蝇蛆病与血细胞中尤其是淋巴细胞之间存在一定的关系；填补了寄生蝇蛆的生活史和形态学鉴定的空白。. 上述结果和数据的建立，为阿拉善双峰驼阴道蝇蛆病的防治、致病机理、新品系的培育等理论研究及应用研究奠定基础，对养驼业的健康发展具有重要意义。