{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T04:42:30Z","timestamp":1790656950465,"version":"4.1.0"},"reference-count":67,"publisher":"American Society for Microbiology","issue":"12","license":[{"start":{"date-parts":[[2024,12,11]],"date-time":"2024-12-11T00:00:00Z","timestamp":1733875200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2024,12,11]],"date-time":"2024-12-11T00:00:00Z","timestamp":1733875200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.asm.org\/non-commercial-tdm-license"}],"content-domain":{"domain":["journals.asm.org"],"crossmark-restriction":true},"short-container-title":["mBio"],"published-print":{"date-parts":[[2024,12,11]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n          <jats:sec>\n            <jats:title\/>\n            <jats:p>\n              The evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the pandemic and post-pandemic periods has been characterized by rapid adaptive changes that confer immune escape and enhanced human-to-human transmissibility. Sequence change is additionally marked by an excess number of C\u2192U transitions suggested as being due to host-mediated genome editing. To investigate how these influence the evolutionary trajectory of SARS-CoV-2, 2,000 high-quality, coding complete genome sequences of SARS-CoV-2 variants collected pre-September 2020 and from each subsequently appearing alpha, delta, BA.1, BA.2, BA.5, XBB, EG, HK, and JN.1 lineages were downloaded from NCBI Virus in April 2024. C\u2192U transitions were the most common substitution during the diversification of SARS-CoV-2 lineages over the 4-year observation period. A net loss of C bases and accumulation of U\u2019s occurred at a constant rate of approximately 0.2%\u20130.25%\/decade. C\u2192U transitions occurred in over a quarter of all sites with a C (26.5%; range 20.0%\u201337.2%) around five times more than observed for the other transitions (5.3%\u20136.8%). In contrast to an approximately random distribution of other transitions across the genome, most C\u2192U substitutions occurred at statistically preferred sites in each lineage. However, only the most C\u2192U polymorphic sites showed evidence for a preferred 5\u2032U context previously associated with APOBEC 3A editing. There was a similarly weak preference for unpaired bases suggesting much less stringent targeting of RNA than mediated by A3 deaminases in DNA editing. Future functional studies are required to determine editing preferences, impacts on replication fitness\n              <jats:italic>in vivo<\/jats:italic>\n              of SARS-CoV-2 and other RNA viruses, and impact on host tropism.\n            <\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>IMPORTANCE<\/jats:title>\n            <jats:p>Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the pandemic and post-pandemic periods has shown a remarkable capacity to adapt and evade human immune responses and increase its human-to-human transmissibility. The genome of SARS-CoV-2 is also increasingly scarred by the effects of multiple C\u2192U mutations from host genome editing as a cellular defense mechanism akin to restriction factors for retroviruses. Through the analysis of large data sets of SARS-CoV-2 isolate sequences collected throughout the pandemic period and beyond, we show that C\u2192U transitions have driven a base compositional change over time amounting to a net loss of C bases and accumulation of U\u2019s at a rate of approximately 0.2%\u20130.25%\/decade. Most C\u2192U substitutions occurred in the absence of the preferred upstream-base context or targeting of unpaired RNA bases previously associated with the host RNA editing protein, APOBEC 3A. The analyses provide a series of testable hypotheses that can be experimentally investigated in the future.<\/jats:p>\n          <\/jats:sec>","DOI":"10.1128\/mbio.02493-24","type":"journal-article","created":{"date-parts":[[2024,10,30]],"date-time":"2024-10-30T15:11:59Z","timestamp":1730301119000},"update-policy":"https:\/\/doi.org\/10.1128\/asmj-crossmark-policy-page","source":"Crossref","is-referenced-by-count":18,"title":["C\u2192U transition biases in SARS-CoV-2: still rampant 4 years from the start of the COVID-19 pandemic"],"prefix":"10.1128","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7964-4700","authenticated-orcid":true,"given":"Peter","family":"Simmonds","sequence":"first","affiliation":[{"name":"Nuffield Department of Medicine, Peter Medawar Building for Pathogen Research, University of Oxford","place":["Oxford, United Kingdom"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"235","reference":[{"key":"e_1_3_2_2_2","doi-asserted-by":"publisher","DOI":"10.1099\/jgv.0.001843"},{"key":"e_1_3_2_3_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41591-020-0820-9"},{"key":"e_1_3_2_4_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41579-023-00878-2"},{"key":"e_1_3_2_5_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41586-020-2895-3"},{"key":"e_1_3_2_6_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.abe8499"},{"key":"e_1_3_2_7_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.cell.2020.06.043"},{"key":"e_1_3_2_8_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41586-022-04411-y"},{"key":"e_1_3_2_9_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.cell.2022.06.005"},{"key":"e_1_3_2_10_2","doi-asserted-by":"publisher","DOI":"10.2807\/1560-7917.ES.2022.27.6.2200042"},{"key":"e_1_3_2_11_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41586-022-04479-6"},{"key":"e_1_3_2_12_2","doi-asserted-by":"publisher","DOI":"10.1128\/mSphere.00408-20"},{"key":"e_1_3_2_13_2","doi-asserted-by":"publisher","DOI":"10.1126\/sciadv.abb5813"},{"key":"e_1_3_2_14_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0237689"},{"key":"e_1_3_2_15_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.bbrc.2020.10.092"},{"key":"e_1_3_2_16_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.isci.2021.102116"},{"key":"e_1_3_2_17_2","doi-asserted-by":"publisher","DOI":"10.1093\/gbe\/evab087"},{"key":"e_1_3_2_18_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.virol.2020.12.018"},{"key":"e_1_3_2_19_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.virol.2015.03.012"},{"key":"e_1_3_2_20_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.0408223102"},{"key":"e_1_3_2_21_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.1153201"},{"key":"e_1_3_2_22_2","doi-asserted-by":"publisher","DOI":"10.1038\/nature01707"},{"key":"e_1_3_2_23_2","doi-asserted-by":"publisher","DOI":"10.1038\/nature01709"},{"key":"e_1_3_2_24_2","doi-asserted-by":"publisher","DOI":"10.1016\/s0092-8674(03)00423-9"},{"key":"e_1_3_2_25_2","doi-asserted-by":"publisher","unstructured":"De Maio N Walker CR Turakhia Y Lanfear R Corbett-Detig R Goldman N. 2021. 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