几种拟地新线虫种间及种内线粒体lsrRNA及cox1基因的多态性

Polymorphisms in Mitochondrial lsrRNA and cox1 Genes Within and Between Members of Pseudoterranova decipiens Complex

对来自世界各地的拟地新线虫共6个种的线粒体基因lsrRNA及cox1序列进行了PCR-SSCP和序列分析.结果显示,lsrRNA基因序列在拟地新线虫种内、种间的变异都比较小,不能提供准确的遗传标记.但cox1基因序列种间变异为0.5%～12.2%,比种内变异(1%～1.7%)大,能提供准确的遗传标记,可用于拟地新线虫姊妹种的鉴定.这些发现有助于拟地新线虫的生活史、传播途径、流行病学、种群遗传学的研究和其相关疾病的诊断.

The nucleotide variation in a portion of the mitochondrial （mt） large subunit of ribosomal RNA gene （lsrRNA） and cytochrome c oxidase subunit 1 gene （cox1） within and between members of the Pseudoterranova decipiens complex ,has examinated using a mutation scanning-sequencing approach. The objective of the study was to assess whether mtDNA sequences provide genetic markers for the identification of members of the Pseudoterranova decipiens complex. A fragment of the lsrRNA approximately 500 bp in length and a fragment of cox1 approximately 450 bp in length were amplified separately by PCR using ^33P-endlabelled primers and the amplicons were analysed by single-strand conformation polymorphism （SSCP）. The results showed that sequence variation in the lsrRNA was low and could not differentiate among the 6 species of Pseudoterranova. whereas sequence difference in the cox1 gene was higher between species than that within species,indicating that cox1 gene sequence provides genetic markers for the accurate identification of the 6 species of Pseudoterranova. These findings should have important implications for studying the life-cycles,transmission patterns,epidemiology and population genetics of members of P. decipines,and for diagnosis of the resultant disease.