Synthesis of morphogenetic proteins by mutants of bacteriophage lambda carrying tandem genetic duplications

Abstract

The post-transcriptional regulation of λ morphogenetic protein synthesis has been investigated using a series of mutant phage carrying tandem duplications of different segments of the morphogenetic genes. By varying the gene dosage of only some of the morphogenetic genes in this way, it is possible to perturb the relative rates of synthesis of different morphogenetic proteins to determine if these rates are controlled by the late proteins themselves by autogenous or feedback regulatory mechanisms. The data indicate that doubling or tripling any of the morphogenetic genes results in a doubling or tripling of the rates of synthesis of the proteins coded by the genes in question with no effect on the rates of synthesis of the proteins coded by nonduplicated genes. These results indicate that the post-transcriptional control of morphogenetic protein synthesis does not involve autogenous or feedback mechanisms. Taken together with previous determinations of the amounts and functional lifetimes of the mRNA coded by different morphogenetic cistrons, the present experiments suggest that the differences in the rates of translation of late messengers are determined by mRNA conformation, ribosome specificity, or other specific translation factors.