Vol. 11, Special Issue 10 (2022)

Author(s):
Dr. Divya Rajawat, Harshit Kumar, Anuradha Panwar, Sonali Sonejita Nayak, Kanika Ghildiyal, Anurodh Sharma, Atul Singh Rajput, Gangula Lokavya Reddy and Manjit Panigrahi

Abstract:
A pan-genome is a collection of genetic sequences distributed throughout all species or groups. The term was first used by Tettelin and his team while he was working on Streptococcus agalactiae strains. The pan-genome can be split into the core, shell, and cloud pan-genome, and classified into two groups; open and close, based on Heap's law. While pan-genomic research began with bacteria, advances in genome sequencing and assembly techniques have enabled the production of pan-genomes for eukaryotic organisms such as fungi, plants, and mammals. The core genome includes genes crucial for the organism's survival and represented as housekeeping genes, while transmission, pathogenicity, and immunity are usually linked with Dispensable genes. As our knowledge of genomic diversity expanded, it became clear that a single reference sequence was insufficient to represent the range of genomic variation observed within species, leading to the development and expansion of the pan-genome concept. Extending pan-genomic studies to higher taxonomic groups will eventually provide the resources needed to investigate the differences between organisms allowing for a comprehensive description of genes, their evolutionary history, and function. Pan-genome s will undoubtedly become widespread in the next decade, rendering the single-reference approach obsolete to genomic research.