抑制性消减杂交技术分析猪链球菌2型毒力相关基因

Genetic difference between Streptococcus suis serotype 2 virulent strain and avirulent strain by suppression subtractive hybridization

以猪链球菌2型四川分离强毒株458#为检测子,国际参考无毒菌株1330#为驱动子,用抑制性消减杂交方法寻找其基因组水平的差异。采用3种不同的限制性内切酶分别酶切458#与1330#基因组获得3套酶切片段,经消减杂交后构建猪链球菌2型强毒株458#特异DNA的差异文库,并对差异序列进行比较分析。结果表明,试验获得了3套差异文库共计42个特异性差异片段,所有差异片段均与已发表的猪链球菌2型05ZYH33株全基因组序列高度同源。构建了具有代表性的猪链球菌2型强毒株与国际无毒参考菌株基因组差异DNA文库,差异片段通过Blast比对,部分差异片段与已知功能基因如转座子、耐药基因、I型限制酶修饰系统、表面蛋白和毒力相关蛋白等有同源性,尚有许多差异片段属于未知功能蛋白或假定蛋白,其中可能包括与猪链球菌2型毒力相关的基因,为进一步分析猪链球菌2型可能的毒力相关基因奠定了基础。

To search potential virulence-related gene of Streptococcus suis serotype 2,the S. suis serotype 2 virulent strain 458^# and avirulent refereflce strain 1330^# were used as tester and driver, respectively. Genomic comparison between strain 458^# and strain 1330s was conducted by suppression subtractive hybridization （SSH）. To get more comprehensive different fragments,we used three restriction enzymes to perform SSH. As results,we screened out 42 fragments from 458^# genome which are absent in 1330^# genome. All these 42 differential fragments were highly homology with other virulence strains 05ZYH33,98HAH33 and P1/7. Among these differential fragments, 11 were located in genomic islands,and some differential fragments may relate with the virulence and pathogenicity of S. suis serotype 2. This study is essential to further research on novel virulence factors and pathogenesis of S. suis serotype 2.