采用通用引物PCR扩增法,测定了辽东湾海域的白色霞水母(Cyanea nozakii)螅状体、碟状体及水母体的18S以及ITS-5.8S r DNA序列,同时利用Gene Bank数据库中已有同源序列对其进行序列分析及系统分析。结果显示,白色霞水母3个个体的18S和ITS...采用通用引物PCR扩增法,测定了辽东湾海域的白色霞水母(Cyanea nozakii)螅状体、碟状体及水母体的18S以及ITS-5.8S r DNA序列,同时利用Gene Bank数据库中已有同源序列对其进行序列分析及系统分析。结果显示,白色霞水母3个个体的18S和ITS-5.8S r DNA序列完全一致。白色霞水母样品的ITS-5.8S r DNA序列与Gen Bank中未知真核生物的序列高度相似(≥99%),推测该物种可能是早期发育阶段(卵、浮浪幼虫或碟状体)的白色霞水母样品。霞水母属不同种间18S r DNA序列经比对后同源序列长度为1709bp,多态位点数33个;比对后ITS1同源序列长度为368bp,其中变异位点203个,简约信息位点数178个,单变异位点21个。基于18S r DNA基因序列的霞水母属种内和种间平均遗传距离分别为0、0.008,而基于ITS1序列的霞水母属种内和种间平均遗传距离分别为0.019、0.284。基于ITS1的种间遗传距离是种内遗传距离的15倍,适合于进行物种鉴定。NJ系统树的结果也表明同种的不同个体各自聚枝,其聚类结果大致与形态分类吻合。研究表明,ITS基因片段在霞水母不同种间变异较大,更适于大型水母种类鉴定、检测及属内种间水平的系统进化研究。展开更多
Giardia lamblia is a widely concerned archezoan. In order to study the phylogeny of G.lamblia, ITS(1 and 2) of ribosome gene(rDNA) and 5.8 SrDNA from various Giardia strains were amplified,cloned and sequenced. A mole...Giardia lamblia is a widely concerned archezoan. In order to study the phylogeny of G.lamblia, ITS(1 and 2) of ribosome gene(rDNA) and 5.8 SrDNA from various Giardia strains were amplified,cloned and sequenced. A molecular phylogenetic tree was constructed with NJ method. After analyzed by DNAMAN software, 12 bases in 2 of the 10 squences were found to be substituted and 1 of the 2 had one base deletion, while the other 8 squences were quite homologous. The constructed phylogenetic tree was consistent with the phylogenic relationship reported previously. All the results show that ITS(1 and 2) and 5.8 SrRNA genes are effective genetic markers for studies of the evolution of Giardia.展开更多
文摘采用通用引物PCR扩增法,测定了辽东湾海域的白色霞水母(Cyanea nozakii)螅状体、碟状体及水母体的18S以及ITS-5.8S r DNA序列,同时利用Gene Bank数据库中已有同源序列对其进行序列分析及系统分析。结果显示,白色霞水母3个个体的18S和ITS-5.8S r DNA序列完全一致。白色霞水母样品的ITS-5.8S r DNA序列与Gen Bank中未知真核生物的序列高度相似(≥99%),推测该物种可能是早期发育阶段(卵、浮浪幼虫或碟状体)的白色霞水母样品。霞水母属不同种间18S r DNA序列经比对后同源序列长度为1709bp,多态位点数33个;比对后ITS1同源序列长度为368bp,其中变异位点203个,简约信息位点数178个,单变异位点21个。基于18S r DNA基因序列的霞水母属种内和种间平均遗传距离分别为0、0.008,而基于ITS1序列的霞水母属种内和种间平均遗传距离分别为0.019、0.284。基于ITS1的种间遗传距离是种内遗传距离的15倍,适合于进行物种鉴定。NJ系统树的结果也表明同种的不同个体各自聚枝,其聚类结果大致与形态分类吻合。研究表明,ITS基因片段在霞水母不同种间变异较大,更适于大型水母种类鉴定、检测及属内种间水平的系统进化研究。
文摘Giardia lamblia is a widely concerned archezoan. In order to study the phylogeny of G.lamblia, ITS(1 and 2) of ribosome gene(rDNA) and 5.8 SrDNA from various Giardia strains were amplified,cloned and sequenced. A molecular phylogenetic tree was constructed with NJ method. After analyzed by DNAMAN software, 12 bases in 2 of the 10 squences were found to be substituted and 1 of the 2 had one base deletion, while the other 8 squences were quite homologous. The constructed phylogenetic tree was consistent with the phylogenic relationship reported previously. All the results show that ITS(1 and 2) and 5.8 SrRNA genes are effective genetic markers for studies of the evolution of Giardia.
