3种冠环线虫rDNA-ITS的PCR扩增及序列分析  

PCR Amplification and Sequence Analysis of rDNA-ITS of Three Species of the Genus Coronocyclus

作　　者：卜艳珍[1] 勾利美[1] 赵鹏飞[1] 王小攀[1] 

机构地区：[1]河南师范大学生命科学学院,河南新乡453007

出　　处：《中国畜牧兽医》2012年第10期33-37,共5页China Animal Husbandry & Veterinary Medicine

基　　金：河南省科技攻关项目(102102110142;112102110032);河南省基础与前沿项目(102300410103);河南省动物学省级重点学科经费(豫教财[2001]160号)

摘　　要：本试验利用PCR扩增3种冠环线虫5个样品的核糖体DNA内转录间隔区(ITS)及5.8S片段,将PCR扩增产物纯化后直接进行序列测定和分析。序列比对和分析结果显示,所测样品ITS1-5.8S-ITS2的长度范围为748～843bp,总变异位点(包括gaps)119个,简约信息位点18个;其中ITS1和ITS2的长度范围分别为367～370bp和228～320bp,变异位点分别为14个和105个,简约信息位点均为9个。所有测试样品的5.8S片段完全相同,长度为153bp。5条序列ITS1区的G+C含量(48.0%～48.5%)明显高于ITS2区(37.7%～40.3%)。通过序列两两比对,3种冠环线虫ITS1和ITS2的种间差异性分别为1.9%～3.5%和5.6%～31.8%;而种内差异性分别为0～0.5%和0～0.9%。并且所测序列与GenBank中已知序列的同源性为99.07%～99.41%。本研究认为,ITS序列可以作为冠环线虫种类鉴定的分子标记。Internal transcribed spacer （ITS） and 5.8S of ribosomal DNA （rDNA） of 3 species （5 samples） of the genus Coronocyclus were amplified and sequenced using polymerase chain reaction （PCR） techniques. Sequence analysis demonstrated that the length of the ITSI-5.8S-ITS2 sequences ranged from 748 to 843 bp, and there were 119 variable sites （including gaps） and 18 parsimony informative sites. The length of the ITS1 sequences ranged from 367 to 370 bp, with 14 variable sites and 9 parsimony informative sites, The length of the ITS2 sequences ranged from 228 to 320 bp, with 105 variable sites and 9 parsi- mony informative sites. The 5.8S gene sequences of all 3 species were identical. For all 3 species, the G＋C content was higher in the ITS1 （48.0% to 48.5%） than in the ITS2 （37.70% to 40.3%）. Pairwise comparison in 5 sequences revealed inter spe- cific differences ranged from 1.9% to 3.5% in the ITS1 and from 5.6% to 31.8% in the ITS2, however, intra specific varia- tion was low （0 to 0.5% and 0 to 0.9 %, respectively）. Furthermore, the homology were 99.07% to 99.41% compared with the sequences in GenBank. The study demonstrated clearly that the internal transcribed spacer sequences provided genetic markers for the species identification of the genus Coronocyclus.

关 键 词：冠环线虫 内转录间隔区(ITS) PCR 序列分析 

分 类 号：Q78[生物学—分子生物学]