Aditya Kumar

By Aditya Kumar and Manju Bansal

Regulation of gene expression is achieved by the presence of cis regulatory elements; these signatures are interspersed in the noncoding region and also situated in the coding region of the genome. These elements orchestrate the gene expression process by regulating the different steps involved in the flow of genetic information. Transcription (DNA to RNA) and translation (RNA to Protein) are controlled at different levels by different regulatory elements present in the genome. Current chapter describes the structural and functional elements present in the coding and noncoding region of the genome. Further we discuss role of regulatory elements in regulation of gene expression in prokaryotes and eukaryotes. Finally, we also discuss DNA structural properties of regulatory regions and their role in gene expression. Identification and characterization of cis regulatory elements would be useful to engineer the regulation of gene expression.

Part of the book: Bioinformatics in the Era of Post Genomics and Big Data

By Bhaswatee Das, Bipasha Choudhury, Aditya Kumar and Vishwa Jyoti Baruah

Mutations in genome are essential for evolution but if the frequency of mutation increases it can evince to be detrimental, for a steady maintenance there exist a detailed complex system of surveillance and repair of DNA defects. Therefore, fault in DNA repair processes raises the probability of genomic instability and cancer in organisms. Genome instability encompasses various aspects of mutations from indels to various somatic variants. The chapter tries to present an overview of how cancer puts up several ways to ensure suppression of the fidelity in our DNA repair system. Cancer cells assure failure of efficient DNA repair mechanisms by innumerous ways, by mutation and epigenetic modifications in repair genes themselves or genes controlling their expression and functions, other by some catastrophic events like kataegis, chromothripsis and chromoplexy. These are clustered mutations taking place at a particular genomic locus which deluge the repair process. Cancer generation and evolution is dependent largely on genome instability, so it applies many strategies to overcome one of its basic obstacles that is DNA repair, targeting these DNA repair genes has also demonstrated to be helpful in cancer therapy; but an intricate understanding of recalcitrant process and mechanisms of drug resistant in cancer will further enhance the potential in them.

Part of the book: DNA