{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,12]],"date-time":"2026-08-12T06:30:22Z","timestamp":1786516222630,"version":"build-2736575974"},"reference-count":48,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,8,12]],"date-time":"2026-08-12T00:00:00Z","timestamp":1786492800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Microbiol."],"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Human metapneumovirus (hMPV) is a leading cause of acute respiratory infections worldwide, yet whole-genome surveillance data remain scarce in eastern China. The evolutionary dynamics of G gene duplication variants and their molecular drivers are poorly characterized.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>From 2024 to 2025, we conducted prospective hMPV surveillance in Nantong, Jiangsu Province, screening 1,602 respiratory specimens by multiplex qPCR. Complete whole-genome sequences were obtained from 26 of 27 positive strains via probe-capture next-generation sequencing, and integrated with 574 global reference genomes. G gene duplication variants (111nt_dup\/180nt_dup) were characterized, O-glycosylation sites predicted (NetOGlyc 4.0), and Bayesian phylodynamic analysis (BEAST v1.10.4) performed on the 111nt_dup lineage.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      The overall detection rate was 1.7% (27\/1,602), with the highest burden in children aged 0\u20135\u202fyears (3.6%) and peak circulation in winter and spring. Phylogenetic analysis revealed a sharp genotype shift among the sequenced strains\u2014from A2.2.2 in 2024 to B2 in 2025 (12\/12 vs. 0\/14;\n                      <jats:italic>p<\/jats:italic>\n                      \u202f&amp;lt;\u202f0.001, Fisher\u2019s exact test)\u2014concordant with contemporaneous observations in Shanghai and Beijing. Globally, 111nt_dup prevalence rose from &amp;lt;10% before 2015 to &amp;gt;90% by 2025 (Cochran-Armitage trend test,\n                      <jats:italic>p<\/jats:italic>\n                      \u202f=\u202f6.86\u202f\u00d7\u202f10\n                      <jats:sup>\u22127<\/jats:sup>\n                      ), whereas 180nt_dup disappeared after 2021. The 111nt_dup lineage displayed near-complete fixation of serine at G protein position 90 (S90, 98.9% vs. 0% in 180nt_dup;\n                      <jats:italic>p<\/jats:italic>\n                      \u202f&amp;lt;\u202f0.001). S90 frequency and 111nt_dup prevalence rose in tight synchrony (Pearson\u2019s\n                      <jats:italic>r<\/jats:italic>\n                      \u202f&amp;gt;\u202f0.95). Bayesian Skyline analysis showed a pandemic-associated population bottleneck (2020\u20132021) followed by rapid recovery to pre-pandemic levels by late 2022.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>The global dominance of 111nt_dup is better explained by lineage-specific molecular selection than neutral drift. Co-occurrence of the 111nt_dup with the predicted S90 O-glycosylation site suggests a model in which predicted glycosylation-driven optimization of the G protein mucin-like domain may enhance fitness, with implications for hMPV vaccine strain surveillance.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fmicb.2026.1915595","type":"journal-article","created":{"date-parts":[[2026,8,12]],"date-time":"2026-08-12T05:54:36Z","timestamp":1786514076000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Genotype turnover and global evolutionary dynamics of G gene duplication variants in human metapneumovirus: insights from prospective surveillance in Nantong, China, 2024\u20132025"],"prefix":"10.3389","volume":"17","author":[{"given":"Xiaolei","family":"Ji","sequence":"first","affiliation":[{"name":"Nantong Center for Disease Control and Prevention","place":["Nantong, Jiangsu, China"]},{"name":"Institute for Applied Research in Public Health, School of Public Health, Nantong University","place":["Nantong, Jiangsu, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhenzhen","family":"Liu","sequence":"additional","affiliation":[{"name":"Nantong Center for Disease Control and Prevention","place":["Nantong, Jiangsu, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiuli","family":"Cai","sequence":"additional","affiliation":[{"name":"Nantong Center for Disease Control and Prevention","place":["Nantong, Jiangsu, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ruyue","family":"Liang","sequence":"additional","affiliation":[{"name":"Nantong Center for Disease Control and Prevention","place":["Nantong, Jiangsu, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lu","family":"Chen","sequence":"additional","affiliation":[{"name":"Nantong Center for Disease Control and Prevention","place":["Nantong, Jiangsu, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xingpei","family":"Ji","sequence":"additional","affiliation":[{"name":"Nantong Center for Disease Control and Prevention","place":["Nantong, Jiangsu, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shiyao","family":"Chen","sequence":"additional","affiliation":[{"name":"Nantong Center for Disease Control and Prevention","place":["Nantong, Jiangsu, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yihua","family":"Sun","sequence":"additional","affiliation":[{"name":"Nantong Center for Disease Control and Prevention","place":["Nantong, Jiangsu, China"]},{"name":"Institute for Applied Research in Public Health, School of Public Health, Nantong University","place":["Nantong, Jiangsu, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chen","family":"Guo","sequence":"additional","affiliation":[{"name":"Nantong Chongchuan Center for Disease Control and Prevention","place":["Nantong, Jiangsu, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,8,12]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"1653","DOI":"10.1038\/s41592-025-02751-x","article-title":"BEAST X for Bayesian phylogenetic, phylogeographic and phylodynamic inference","volume":"22","author":"Baele","year":"2025","journal-title":"Nat. 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