What is meant by Gene Expression?

The synthesis of protein under the influence of gene is called Gene Expression. All human cells are derived from a single cell, fertilized egg or zygote. Therefore, all cells contain the same genetic information. However, a cell from the gastrointestinal epithelium is different from a cell of the central nervous system or from the liver, both by structure and function. In a cell about 90% of DNA is permanently inactive. His tones and specific proteins help in this inactivation process and consequent differentiation.

The fundamental dogma of molecular biology is that DNA produces RNA (ribonncleic acid), which in turn produces proteins. Thus, the genetic information in the DNA specifying particular functions is converted into an RNA copy by the process of transcription, which is then translated into protein. The action of the protein then produces the phenotype. Current scientific evidence indicates that only 10% of the human DNA contains genes, i.e., those sequences that are transcribed and translated.

In simple terms, gene expression is the process by which a gene's DNA sequence is converted into the structure and functions of a cell. Gene expression is a multi- step process that begins with transcription of DNA into messenger RNA (mRNA).