ABSTRACT
Abstract RNA is synthesized using one of the DNA strands as a template and has the same chemical structure except that thymine is replaced by uracil (U). Some RNA molecules can be the end product in themselves and some can in turn be used as a template for the creation of other molecules, proteins, by a process called ‘translation’. Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product. Bacterial genomes usually contain several thousand different genes. Some of the gene products are required by the cell under all growth conditions and are called ‘housekeeping genes’. Gene regulation can occur at three possible places in the production of an active gene product. First, the transcriptional regulation second, the translational regulation and third the post-transcriptional or Post-translational regulation mechanisms. The regulatory mechanisms controlling gene expression are typically discovered by mutational analysis. Cis-acting molecules act upon and modulate the expression of physically adjacent, operably linked polypeptide-encoding sequences. Trans-acting factors affect the expression of genes that may be physically located very far away, even on different chromosomes. The expression of a particular gene may be regulated by the concerted action of both cis and trans-acting elements. Since changes in gene expression levels are thought to underlie many of the phenotypic differences between species, identifying and characterizing the regulatory mechanisms responsible for these changes is an important goal of molecular biology. The main aim of this chapter is to provide scattered information of RNA sequencing and gene expression in gathered form to the scientist and researchers.
