目的:探索溶源性噬菌体诱发为烈性噬菌体的分子机理,以防控生产中溶源性噬菌体的随机爆发。方法:提取苏云金杆菌噬菌体基因组DNA,获取片段D并克隆测序,分析ogr基因与其它噬菌体的同源性。结果:ogr基因位于片段D中,为216bp,编码72个氨基酸,分子量为3.79kD。Blast分析表明,D片段与其它噬菌体的同源性低于25%。结论:从同源性的比较中推测该噬菌体为Escherichia coli K12家族,其中含有的晚期基因可能参与晚期表达的过程。 Objective: To explore the molecular mechanism induced by lysogenic phage into potent bacteriophages to prevent random outbreak of lysogenic phage during production. Methods: Bacillus thuringiensis phage genomic DNA was extracted, fragment D was cloned and sequenced, and the homology of ogr gene with other phage was analyzed. RESULTS: The ogr gene was located in fragment D and was 216 bp, encoding 72 amino acids with a molecular weight of 3.79 kD. Blast analysis showed that the D fragment shares less than 25% homology with other phage. Conclusion: The comparison of homology suggests that the phage is Escherichia coli K12 family, which contains the late genes may be involved in the late expression process.