A collection of amber mutants of bacteriophage T5 was analysed using an complementation test and assigned to 21 complementation groups. The incomplete phage structures produced by T5 amber mutant infection of the non-permissive host were examined. The mutants were allocated to four phenotypic types, as defined by an complementation test: those which produced functional heads, H; those which produced functional tails, T; those which produced inactive heads and functional tails, HI + T; and those which did not synthesize either heads or tails, 0. Functional heads and inactive heads were indistinguishable in shape and size in the electron microscope. Four different patterns of DNA metabolism were observed when different amber mutants were grown under non-permissive conditions. They were the wild-type pattern (D) in which host DNA degradation was followed by synthesis of phage DNA, host DNA degradation without phage DNA synthesis (D0), neither host DNA degradation nor phage DNA synthesis (DD0) and host DNA degradation with slight DNA synthesis (DS). Upon infection of the non-permissive host with representatives of different complementation groups of mutants either normal lysis occurred or bacterial growth ceased without subsequent lysis. The phenotypic characteristics of the amber mutants were used for partial elucidation of the functions of the affected genes.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error