摘要
对烟粉虱内共生菌16SrDNA的酶切结果及部分生物体16SrDNA的(G+C)%分析结果表明:烟粉虱初生内共生菌的16SrDNA能够被EcoRI酶切成两个片段、而不能够分别被BamHI与SacI酶切;烟粉虱次生内共生菌的16SrDNA没有BamHI内切酶位点、而能够分别被EcoRI或Sac I酶切成大小不同的两个片段。(G+C)mol%与菌的分类地位有关,同时还与菌的可培养能力有关。Proteobacteriaγ亚纲的烟粉虱初生内共生菌与α亚纲的Rickettsia、线粒体的16SrDNA相似,富含(A+T)mol%,具低的(G+C)mol%。而γ亚纲的次生内共生菌及大肠杆菌与β亚纲的mealybugs初生内共生菌的16SrDNA相似,富含(G+C)mol%。说明初生内共生菌可能与烟粉虱同时发生,并且形成一种非常紧密的共生关系,次生内共生菌与烟粉虱关系松散一些,其特性近似于自由生活的细菌,更有可能获得纯培养体。16SrDNA的系统进化树表明,烟粉虱次生内共生菌属于Proteobacteriaγ-3亚纲,而初生内共生菌属于Proteobacteriaγ亚纲的另一分支。
The studies on enzymes digested sites and （G ＋ C）mol% of 16S rDNA gene from endosymbionts in B. tabaci were conducted. The results showed that： 16S rDNA from primary endosymbiont in B. tabaci could be digested into two segments by EcoR I,but not by BamH I or Sac I. 16S rDNA from secondary endosymbiont in B. tabaci could be digested into two segments by EcoR I or Sac I respectively, but not by BamH I. The （G ＋ C）mol% of 16S rDNA varied according to creature species and culturable characters. For example, 16S rDNA of primary endosymbiont （ Proteobacteria γ subdivision） in B. tabaci were as rich in （A ＋ T）mol% and poor in（G ＋ C）mol% as 16S rDNA of Rickettsia and mitochondria （Proteobacteria a subdivision）, which are cell ware or unculturable microbes. The 16S rDNA from secondary endosymbiont （Proteobacteria γ subdivision） in B. tabaci and primary endosymbiont （ Proteobacteria β subdivision） in mealybugs, both were unculturable, were as rich in （ G ＋ C） mol% as those of E. coli （Proteobacteria γ subdivision）, a kind of culturable bacterium. As a result, primary endosymbiont was a concurrence and concerted evolution with B. tabaci. Secondary endosymbiont was similar to free-living bacteria and might be easier to be cultured. Molecular phylogenetic trees based on 16S rDNA of different creatures showed that secondary endosymbiont in B. tabaci was Proteobacteria γ-3 subdivision. Primary endosymbiont in B. tabaci was aonther Proteobacteria γ subdivision.
出处
《微生物学通报》
CAS
CSCD
北大核心
2007年第3期487-491,共5页
Microbiology China
基金
国家重点基础研究发展规划项目(No.2002CB111400)
