Brüssow H, Bruttin A
Nestlé Research Centre, Nestec Ltd., Vers-chez-les-Blanc, Lausanne, Switzerland.
Virology. 1995 Oct 1;212(2):632-40. doi: 10.1006/viro.1995.1521.
The temperate Streptococcus thermophilus bacteriophage phi SFi21 showed an 38-kb-long double-stranded DNA genome with cohesive ends. A single integration site was used in lysogens established in three different S. thermophilus strains. The attP and attB sites were localized on the restriction map of phage DNA and by hybridization on pulsed field separated bacterial DNA. All laboratory-established lysogens showed in addition to integrated prophage DNA unintegrated monomer phage DNA with unligated cos sites. The genetic relatedness of phi SFi21 DNA with DNA from lytic phages was studied in dot blot and Southern blot hybridization by using individual restriction fragments of phiSFi21 DNA as probes. Lytic group I phages hybridized with fragments of the central and the right part of the phiSFi21 genome but failed to hybridize with a fragment joining both parts. Lytic group II phages showed hybridization with the right half of the phiSFi21 genome. In lytic group IV phages, biologically a heterogeneous group, many different combinations of cross hybridization were detected in accordance with the hypothesis of the modular evolution of phage genomes.
温和型嗜热链球菌噬菌体phi SFi21具有一个38kb长的双链DNA基因组，其末端具有粘性。在三种不同的嗜热链球菌菌株中建立的溶原菌使用了单个整合位点。通过噬菌体DNA的限制性图谱定位以及在脉冲场分离的细菌DNA上进行杂交，确定了attP和attB位点。除了整合的原噬菌体DNA外，所有实验室建立的溶原菌还显示出带有未连接粘性末端位点的未整合单体噬菌体DNA。通过使用phiSFi21 DNA的各个限制性片段作为探针，在斑点印迹和Southern印迹杂交中研究了phi SFi21 DNA与裂解性噬菌体DNA的遗传相关性。I组裂解性噬菌体与phiSFi21基因组的中部和右部片段杂交，但未能与连接这两部分的片段杂交。II组裂解性噬菌体与phiSFi21基因组的右半部分杂交。在生物学上属于异质组的IV组裂解性噬菌体中，根据噬菌体基因组模块化进化的假设，检测到了许多不同的交叉杂交组合。
