IIT Jodhpur researchers identify COVID-19 RNA variations, their implications
Feb 10, 2022
New Delhi [India], February 10 : A multi-institutional team led by the Indian Institute of Technology (IIT) Jodhpur used state-of-the-art genomic sequencing methods to identify variations in the Ribonucleic acid (RNA) of the COVID-19 virus.
"The scientists have also studied the fixation of these intra-host variations into extra-host variations and mutations that lead to variants. The results of the two-phase study have been published in the journal, Nucleic Acid Research," IIT Jodhpur said in a statement.
"An important distinction of this research study is that it was conducted primarily by a team of computational graduates from across distant locations, proving that the pandemic has generated novel cooperation, sharing, and resource-sharing modes for innovative research," IIT Jodhpur said.
The institute further said that the RNA structure of the COVID-19 virus frequently undergoes minor modifications within the host cells (intra-host variations). These modifications occur at the nucleotide level - nucleotide being the building block of the RNA molecule. Many of these intra-host variations are caused by enzymes present in the host cell as an immune response.
Thus, many of these variations are harmless or even destructive to the virus itself. However, some variations can enhance the survivability of the virus, and become fixed as extra-host variations that could potentially lead to variants-of-concern, said IIT Jodhpur.
The research team studied intra-host Single Nucleotide Variations (iSNV) using a sequencing platform called Illumina. During Phase 1 of the project in 2020, scientists analyzed the RNA structure of virus samples collected from China, Germany, Malaysia, the United Kingdom, the United States, and different subpopulations of India to map the intrahost single-nucleotide variants (iSNV) across the RNA structure of the virus.
Prof Mitali Mukerji, Head, Department of Bioscience and Bioengineering, IIT Jodhpur, who co-led the study, said, "One of the most important aspects to managing the COVID-19 pandemic is to unravel the genetic structure of the virus and pick up early warning signatures."
"We observed 16,410 iSNV sites spanning the viral genome, and a high density of alterations were present in critical areas that could alter or override the body's ability to trigger an immune response," she added.
The team has observed similar patterns across populations and waves of the pandemic. It also tracked the iSNVs over time to see if the variants produced inside the host cells can persist outside, thereby becoming fixed as SNVs. They found that by 30 June 2021 about 80 per cent of the iSNV sites they had identified in 2020 became fixed as SNVs. The conversion of iSNVs to SNVs was substantiated in Phase II studies that showed iSNVs were found in most of the Delta and Kappa variants before their fixation as SNVs by February 2021.
"The evolution of SNVs from iSNVs can affect vaccine response by altering the antibody generation in infected individuals," Prof Mukerji said on the implications of their findings. The identification of iSNVs can also help in the identification of key sites in the viral RNA that are important for its survival and spread.
The research was initiated at the Council of Scientific and Industrial Research Institute of Genomics and Integrative Biology, New Delhi and was led by IIT Jodhpur and the Institute of Life Sciences, Bhubaneswar.
Other collaborating institutes include the Academy of Scientific and Innovative Research, Ghaziabad, Council of Scientific and Industrial Research - Center for Cellular and Molecular Biology, Hyderabad and National Center for Disease Control, New Delhi.
