Nonidentical times of gene expression in two strains of [formula omitted] with mapping differences

Abstract

α-aminoadipic acid reductase activity and galactokinase activity were both found to be periodically synthesized in synchronized cultures of baker's yeast. In strain S288C (wild type map of Chromosome II) the synthetic period of the reductase began at 0.25–.35 fraction of a generation while that for the kinase began at 0.45–.55 fraction of a generation. However, in strain 61009 where gal 1 (the gene for galactokinase) and lys 2 (the gene for α-aminoadipic acid reductase) map in entirely different positions, the respective enzyme activities begin to accumulate at 0.15-0.25 and 0.65-0.75 fraction of a generation. These results indicate that transcriptional control of the timing of periods of enzyme synthesis in at least one eucaryote is influenced by the position of the structural gene on the chromosome.