病毒的遗传分析 最便利的遗度工具
病毒的遗传分析 最便利的遗传工具
噬菌体学派教皇 德尔布吕克
噬菌体学派教皇 • 德尔布吕克
噬菌体学习要点 体如何繁殖 ·噬菌体的在细菌染色体上如何插 入和切出? 噬菌体的遗传特性如何检测? 噬菌体DNA如何排列?
噬菌体学习要点 • 噬菌体如何繁殖？ • 噬菌体的在细菌染色体上如何插 入和切出？ • 噬菌体的遗传特性如何检测？ • 噬菌体DNA如何排列？
噬菌体作为遗传工具的优点 增值周期短 几毫升培养液中可得到庞大的噬菌 体群体。 ·基因组小。 ·突变体类剋多。可进行重组奥验, 便于筛选
噬菌体作为遗传工具的优点 • 增值周期短 • 几毫升培养液中可得到庞大的噬菌 体群体。 • 基因组小。 • 突变体类型多，可进行重组实验， 便于筛选
噬菌体的繁殖 Presence of infecting pha Bacterial growth produces progeny phages that results uniform coverage (a "lawn") in a clearing plaque) in where no phage is present. a small region Bacterial bactor Figure 8.16 Plaque formation. (A) In the absence of a phage, bacte rial cells grow and form a translucent Lawn Bacterial cells deposited in the vicinity of a phage are infected and lyse Progeny phages diffusing outward from the riginal site infect other cells and cause their lysis. Becaase of phage infection and lysis, no bactenia can grow in a small region atound the site et each phage particle originally present in the medium. The area devoid of bacteria remains transparent and is called a plaque. (B) Large plaques in a lawn of E, cl formed by infection with a mutant of bacteriophage A. Each plaque results from an inital iniection by a single bac-
噬菌体的繁殖