Gene Expression in Prokaryotes

Prokaryotes are single-celled organisms which doesn't have nucleus. Their DNA are free floating in the cell cytoplasm. In prokaryotes, proteins are synthesized by transcription and translation. The transcription stops when the resulting protein is not required which depends mainly on their immediate environment like presence and absence of nutrients. Hence, gene expression in prokaryotes occurs primarily at the level of transcription. Operons regulate the gene expression in prokaryotes like bacteria. François Jacob and Jacques Monod first identified operon in 1961. A cluster of functionally related genes controlled through shared operator is called operons. They consist of multiple genes which are grouped together with a promoter and an operator. The presence of operons is experimentally determined using northern blot, RT-PCR, and gene expression arrays (Ramos et al. 2013).