Mutational Signatures and Heterogeneous Host Response Revealed Via Large-scale Characterization of SARS-CoV-2 Genomic Diversity
Overview
Affiliations
To dissect the mechanisms underlying the inflation of variants in the Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) genome, we present a large-scale analysis of intra-host genomic diversity, which reveals that most samples exhibit heterogeneous genomic architectures, due to the interplay between host-related mutational processes and transmission dynamics. The decomposition of minor variants profiles unveils three non-overlapping mutational signatures related to nucleotide substitutions and likely ruled by APOlipoprotein B Editing Complex (APOBEC), Reactive Oxygen Species (ROS), and Adenosine Deaminase Acting on RNA (ADAR), highlighting heterogeneous host responses to SARS-CoV-2 infections. A corrected-for-signatures analysis demonstrates that such mutational processes are affected by purifying selection, with important exceptions. In fact, several mutations appear to transit toward clonality, defining new clonal genotypes that increase the overall genomic diversity. Furthermore, the phylogenomic analysis shows the presence of homoplasies and supports the hypothesis of transmission of minor variants. This study paves the way for the integrated analysis of intra-host genomic diversity and clinical outcomes of SARS-CoV-2 infections.
Yang Y, Zhang X, Chen T, Wu F, Huang Y, Qu Y Mol Biol Evol. 2025; 42(2).
PMID: 39823310 PMC: 11796089. DOI: 10.1093/molbev/msaf009.
C→U transition biases in SARS-CoV-2: still rampant 4 years from the start of the COVID-19 pandemic.
Simmonds P mBio. 2024; 15(12):e0249324.
PMID: 39475243 PMC: 11633203. DOI: 10.1128/mbio.02493-24.
Goldswain H, Penrice-Randal R, Donovan-Banfield I, Duffy C, Dong X, Randle N Genome Med. 2024; 16(1):89.
PMID: 39014481 PMC: 11251137. DOI: 10.1186/s13073-024-01360-1.
Chen D, Randhawa G, Soltysiak M, de Souza C, Kari L, Singh S JMIR Bioinform Biotechnol. 2024; 3(1):e42243.
PMID: 38935965 PMC: 11135226. DOI: 10.2196/42243.
Shempela D, Chambaro H, Sikalima J, Cham F, Njuguna M, Morrison L Int J Mol Sci. 2024; 25(12).
PMID: 38928045 PMC: 11203853. DOI: 10.3390/ijms25126338.