GENETIC REPLICATION AND MACROMOLECULAR SYNTHESIS IN TEMPERATE BACTERIOPHAGES

摘要

- It has been confirmed that the block imposed by the immunity of a lysogenic cell to the replication of homologous phage chromo¬somes cannot be bypassed in trans : the immunity repressor thus directly acts on the replication process.n- Genetic and functional analysis of "early" conditional and abso¬lute defective mutants of λ allowed a precise location of the mutational sites and an assignement of the mutations to cistrons.n- It has been shown that several genes of the X chromosome (essentially the whole right arm of the chromosome) are not directly controlled by the immunity repressor, since their expression can be induced in the prophage state by heteroimmune superinfection. The results indicate that the X chromosome comprises more than one unit of expression and that the expression of later functions is switched on by a diffusible product of an earlier one.