EXPORT AND INTERCELLULAR TRANSFER OF DNA VIA MEMBRANE BLEBS OF NEISSERIA-GONORRHOEAE
EXPORT AND INTERCELLULAR TRANSFER OF DNA VIA MEMBRANE BLEBS OF NEISSERIA-GONORRHOEAE
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DOI：
10.1128/jb.171.5.2499-2505.1989
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发表时间：
1989-05-01
影响因子：
3.2
通讯作者：
JUDD, RC
中科院分区：
文献类型：
--
作者：
DORWARD, DW;GARON, CF;JUDD, RC
在淋病奈瑟菌培养物中经常观察到自然形成的膜泡物质。对该材料进行纯化并分析蛋白质、脂多糖和核酸含量。两种富含气泡的组分（称为 BI 和 BII）的电泳蛋白谱是不同的，只有 BII 含有脂多糖和外膜蛋白 I 和 III。两种级分均含有 RNA、环状 DNA 和线性 DNA。外源胰腺 DNase I 似乎可以水解组分 BI 中所有与泡相关的 DNA 和组分 BII 中的线性 DNA。与 BII 级分相关的环状 DNA 分子抵抗消化。气泡部分的电子显微镜验证了它们的 DNA 含量。在进行显微镜检查之前用戊二醛固定气泡可以防止内部 DNA 的释放。这种固定对 BI 的显微照片几乎没有产生什么变化；然而，在固定的 BII 制剂中仅观察到痕量 DNA。将野生型淋球菌在 DNase 和从抗生素抗性菌株中纯化的泡的混合物中孵育，可实现青霉素酶特异性 R 质粒的有效交换。受体整合的质粒独立于内源和外源染色体链霉素抗性标记。这些体外结果表明，淋病奈瑟菌形成的泡可能有助于体内细胞间转移质粒，这可能构成了这些细菌中先前未探索的遗传交换机制。
Naturally elaborated membrane bleb material is frequently observed in cultures of Neisseria gonorrhoeae. This material was purified and analyzed for protein, lipopolysaccharide, and nucleic acid content. The electrophoretic protein profiles of two bleb-rich fractions, called BI and BII, wer distinct, with only BII containing lipopolysaccharide and outer membrane proteins I and III. Both fractions contained RNA, circular DNA, and linear DNA. Exogenous pancreatic DNase I appeared to hydrolyze all bleb-associated DNA in fraction BI and the linear DNA in fraction BII. The circular DNA molecules associated with fraction BII resisted digestion. Electron microscopy of the bleb fractions verified their DNA content. Fixing blebs with glutaraldehyde before mounting them for microscopy prevented release of internal DNA. Such fixation produced little change in the micrographs of BI; however, only traces of DNA were observed in fixed BII preparations. Incubation of wild-type gonococci in mixtures of DNase and blebs purified from antibiotic-resistant strains resulted in efficient exchange of penicillinase-specifying R plasmids. Recipients incorporated plasmids independently of endogenous and exogenous chromosomal streptomycin resistance markers. These in vitro results suggest that bleb formation by N. gonorrhoeae may serve to transfer plasmids interecellularly in vivo, perhaps constituting a previously unexplored genetic exchange mechanism in these bacteria.