骆驼斯氏副柔线虫在传播媒介角蝇体内发育过程的研究

发布时间：2018-01-31 18:26

  本文关键词： 骆驼 斯氏副柔线虫 角蝇 发育过程 18S rDNA　出处：《内蒙古农业大学》2015年硕士论文　论文类型：学位论文

【摘要】：骆驼斯氏副柔线虫病(Parabronemosis)是山斯氏副柔线虫(Parabronema skrjabini)寄生于骆驼真胃引起的一种严重危害养驼业的寄生性线虫病,该病的传播媒介为西方角蝇(Haematobia irritans)和截脉角蝇(Haematobia titillans)。为了弄清斯氏副柔线虫在角蝇体内的发育过程,本研究从骆驼生活环境的驼粪和牛粪中,大量收集疑似角蝇幼虫,依据角蝇幼虫龄期划分标准,并通过分子生物学方法鉴定其为角蝇各龄期幼虫；继而大量剖解角蝇各龄期幼虫,在其体内寻找疑似斯氏副柔线虫幼虫,利用分子生物学方法对找到的疑似斯氏副柔线虫幼虫进行鉴定,统计角蝇各龄期幼虫体内斯氏副柔线虫幼虫的感染率并观察其形态特征。与此同时,对内蒙古地区西方角蝇和截脉角蝇18S rDNA基因全序列进行克隆和测定,比较两种角蝇18S rDNA基因序列及其与GenBank中已登录的9种双翅目昆虫18S rDNA基因序列的同源性,并利用它们的全序列和最保守同源区构建系统进化树,以确定两种角蝇在双翅目昆虫中的位置,并为双翅目不同科属昆虫之间的差异性及其分子系统进化特点的相关研究提供依据。结果表明：①从骆驼生活环境的驼粪和牛粪中收集的角蝇幼虫被证实是角蝇各龄期幼虫,通过分子生物学方法鉴定角蝇幼虫时,改良酚/氯仿抽提法是提取角蝇各龄期幼虫DNA的最佳方法。②角蝇感染斯氏副柔线虫虫卵始于其幼虫阶段,其Ⅰ、Ⅱ、Ⅲ期幼虫均可感染,且平均感染率分别为4.48%、5.66%和4.78%。角蝇各龄期幼虫体内的斯氏副柔线虫幼虫在光学显微镜下的形态结构相似,虫体头端钝圆,口针明显并位于其顶端；尾部尖细向腹面弯曲,肛门开口于虫体近末端；其内部结构比较简单,可以看到食道,且能分出食道肌质部和腺质部,肠与食道后端相连。③西方角蝇和截脉角蝇的18S rDNA基因全序列长度均为1984bp,二者的同源性为96.4%,存在73个识别位点,其中截脉角蝇的18S rDNA基因序列系国内外首次报道。11种双翅目昆虫18S rDNA基因序列具有三段保守程度较高的同源区,分别相当于西方角蝇18S rDNA基因序列的320bp～693bp、848bp～1181bp、1569bp～1849bp,其中第一段为最保守同源区；利用其构建的系统发育树对11种双翅目昆虫进行分类,比18SrDNA基因全序列构建的系统发育树更符合传统形态学分类结果。本研究首次在角蝇各龄期幼虫中分离鉴定出斯氏副柔线虫幼虫,并对其形态特征进行了描述,这不仅填补了国内外对上述研究的空白,还为弄清斯氏副柔线虫在传播媒介角蝇体内的发育过程奠定了基础。
[Abstract]:Parabronema skrjabinii of Camel is Parabronema skrjabinii. Parasitic nematode parasitic disease caused by camel eurogastric disease that seriously endangers camel farming. The transmission vectors of the disease are Haematobia irritanss and Haematobia titillanss. In order to understand the developmental process of nematode skeldahl in hornfly. In this study, a large number of suspected hornfly larvae were collected from camel dung and cow dung in the living environment of camels. Then, a large number of larvae of different ages of hornfly were dissected, and the suspected larvae of Pararinus skrjabini were searched in its body, and the suspected larvae were identified by molecular biological method. The infection rate and morphological characteristics of nematode skeldahl larvae in different larvae of hornfly were analyzed. The 18s rDNA gene was cloned and sequenced from western keratflies and C. truncus in Inner Mongolia. To compare the 18s rDNA gene sequence of two species of hornfly and its homology with the 18s rDNA gene sequence of 9 species of Diptera insects registered in GenBank. The phylogenetic tree was constructed by using their whole sequence and most conserved homologous region to determine the position of two species of hornflies in Diptera insects. It also provides a basis for the study of the differences among different families and genera of Diptera and the characteristics of molecular phylogeny. The results show that:. 1 the larvae collected from camel dung and cow dung were proved to be larvae of different ages. The modified phenol / chloroform extraction method is the best method for extracting DNA from the larvae of keratflies by molecular biological method. Stage 鈪，

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