Abstract:

Objective To compare the diversity of mitochondrial genomes of Angiostrongylus cantonensis in the mainland of China. Methods According to the population genetic of A. cantonensis，seven female worms were selected to characterize the mi? tochondrial（MT）genomes. Twelve primer pairs based on known MT genome（GQ398121）were used for PCR. The target frag? ments were sequenced and aligned. The gene localization，genome structure，composition of nucleotide，distribution of variable sites，and phylogeny were analyzed by employing multiple softwares. Results Five distinct types were identified from seven com? plete MT genomes. They were similar in size and structure，i.e.，ranging 13 491?13 502 bp，including 12 protein?coding genes，2 ribosomal genes，22 tRNA genes，and 2 major non?coding regions. All the genes were localized at the same strand and had the same transcription direction. A total of 745 variable sites were identified，accounting for 5.5%. Among the variable sites，59 were deletion/insert mutations，105 transversions，and 581 transitions. The variable sites distributed evenly at the complete genome. Conclusion The study reveals the mutation profile in the whole MT genome of A. cantonensis and thus will facilitate the develop? ment of intraspecific differential diagnosis.

Key words: Angiostrongylus cantonensis； Mitochondrial genome； Comparative analysis

摘要：

目的 目的 比较我国大陆地区广州管圆线虫线粒体基因组的多态性。 方法 方法 在种群遗传学研究基础上， 选取7条雌虫进行线粒体基因组的测定。根据广州管圆线虫线粒体基因组已知序列 （GQ398121） 设计12对引物， 进行PCR扩增， 并对目的片段进行测序和拼接。利用多种生物学软件对测定的线粒体基因组进行基因定位、 结构图绘制、 核苷酸及变异位点分析、 进化关系分析。结果 结果 获得5个不同遗传类型的线粒体基因组。这些基因组的大小相似、 结构相同， 即 13 491～13 502对碱基， 含12个蛋白编码基因， 2个核糖体基因， 22个tRNA基因， 2个较大的非编码区。上述基因紧密地排列在同一条DNA链上， 并具有相同的转录方向。通过对这些基因组的比对发现， 变异位点745个， 占整个基因组的5.5%。其中， 缺失/插入突变59个， 碱基颠换105个， 碱基转换581个。这些突变位点均匀地分布在整个线粒体基因组中。结论 结论本研究提供了丰富的广州管圆线虫线粒体基因的突变位点， 为构建种内鉴别诊断技术提供了基础。

关键词: 广州管圆线虫； 线粒体基因组； 比较分析