Zhu X, Chilton N B, Jacobs D E, Boes J, Gasser R B
Department of Veterinary Science, The University of Melbourne, Werribee, Victoria, Australia.
Int J Parasitol. 1999 Mar;29(3):469-78. doi: 10.1016/s0020-7519(98)00226-4.
The sequences of the nuclear ribosomal DNA region spanning the first internal transcribed spacer, the 5.8S rRNA gene and the second internal transcribed spacer were determined for Ascaris samples from pigs and humans from different geographical regions. The sequences of the 5.8S gene and the second internal transcribed spacer were the same for all samples examined, whereas all Ascaris samples from humans had six (1.3%) nucleotide differences in the first internal transcribed spacer compared with those from pigs. These differences provided some support for the existence of separate species of Ascaris or population variation within this genus. Using a nucleotide difference within a site for the restriction enzyme HaeIII, a PCR-linked restriction fragment length polymorphism method was established which allowed the delineation of the Ascaris samples from pigs and humans used herein. Exploiting the sequence differences in the first internal transcribed spacer, a PCR-based single-strand conformation polymorphism method was established for future analysis of the genetic structure of pig and human Ascaris populations in sympatric and allopatric zones.
测定了来自不同地理区域猪和人的蛔虫样本中，跨越第一个内部转录间隔区、5.8S rRNA基因和第二个内部转录间隔区的核糖体DNA区域序列。在所检测的所有样本中，5.8S基因和第二个内部转录间隔区的序列相同，而与猪的蛔虫样本相比，所有人的蛔虫样本在第一个内部转录间隔区有六个（1.3%）核苷酸差异。这些差异为蛔虫属内存在不同物种或种群变异提供了一定支持。利用限制性内切酶HaeIII在一个位点的核苷酸差异，建立了一种PCR连锁限制性片段长度多态性方法，可用于区分本文所使用的猪和人的蛔虫样本。利用第一个内部转录间隔区的序列差异，建立了一种基于PCR的单链构象多态性方法，用于未来分析同域和异域区域猪和人蛔虫种群的遗传结构。
