Lim D, Trivedi H, Nath K
Department of Biology, C.W. Post Campus of Long Island University, Brookville, New York 11548, USA.
DNA Res. 1994;1(3):115-22. doi: 10.1093/dnares/1.3.115.
The chromosomal DNA of four strains of Gardnerella vaginalis were digested with rare cutting restriction enzymes and analyzed by pulsed-field gel electrophoresis (PFGE). The four strains studied were two clinical isolates (GVP 004 & GVP 007) and two American Type Culture Collection strains (ATCC 14018 & ATCC 14019). The restriction enzyme SfiI generated two DNA fragments of about 0.6 Mb and 1.1 Mb in all four strains giving a G. vaginalis genome size of about 1.7 Mb. A similar genome size was calculated utilizing two more GC-rich sequence specific restriction endonucleases, NotI and AscI. When digested with AscI, the chromosomal DNA of all four strains gave rise to 11 to 12 DNA fragments ranging between 0.01 Mb to 0.43 Mb. DNA from the two clinical isolates were digested by NotI (yielding 7 to 9 fragments), while the DNA from the two ATCC strains were resistant to NotI digestion. In contrast the clinical isolates, DNA from the two ATCC strains gave an identical profile for all restriction endonucleases tested. From double digestion experiments, the two SfiI sites could be localized on two AscI fragments. From these PFGE studies, it is concluded that the G. vaginalis genome is a circular DNA that ranges between 1.67 Mb and 1.72 Mb in size.
用稀有切割限制酶消化4株阴道加德纳菌的染色体DNA，并通过脉冲场凝胶电泳（PFGE）进行分析。所研究的4株菌株为2株临床分离株（GVP 004和GVP 007）以及2株美国典型培养物保藏中心菌株（ATCC 14018和ATCC 14019）。限制酶SfiI在所有4株菌株中产生了两条分别约为0.6 Mb和1.1 Mb的DNA片段，得出阴道加德纳菌的基因组大小约为1.7 Mb。利用另外两种富含GC序列特异性的限制内切酶NotI和AscI计算得出了相似的基因组大小。用AscI消化时，所有4株菌株的染色体DNA产生了11至12条DNA片段，大小在0.01 Mb至0.43 Mb之间。来自2株临床分离株的DNA用NotI消化（产生7至9条片段），而来自2株ATCC菌株的DNA对NotI消化具有抗性。与临床分离株相反，来自2株ATCC菌株的DNA对所有测试的限制酶都呈现相同的图谱。通过双酶切实验，两个SfiI位点可定位在两条AscI片段上。从这些PFGE研究得出结论，阴道加德纳菌的基因组是环状DNA，大小在1.67 Mb至1.72 Mb之间。
