Gene Control in Bacteria

Abstract

At any one time most of the genes in an organism are not being actively transcribed. One of the significant ways in which a cell can respond to its environment is to switch certain genes off and others on. Circumstances that have been found to affect cells in this way include heat, light and changes in the concentration of substrates or products. Cells in multi-cellular organisms may respond to these stimuli directly or via changes in hormone levels. For a few genes from bacteria and viruses, the story from the external stimulus to the gene response is more or less completely known. Our knowledge of such processes in eukaryotes is much more fragmentary.