article published yes David Field author 419049E2-F248-11E8-B48F-1D18A9856A870000-0002-4014-8478 Sean Stankowski author 43161670-5719-11EA-8025-FABC3DDC885E Taylor Reiter author Jitka Polechova author Desmond Bradley author Daniel M. Richardson author Annabel Whibley author Arka Pal author 6AAB2240-CA9A-11E9-9C1A-D9D1E56974250000-0002-4530-8469 Daria Shipilina author 428A94B0-F248-11E8-B48F-1D18A9856A870000-0002-1145-9226 Louis Boell author Melinda Pickup author 2C78037E-F248-11E8-B48F-1D18A9856A870000-0001-6118-0541 Yongbiao Xue author Enrico Coen author Nicholas H Barton author 4880FE40-F248-11E8-B48F-1D18A9856A870000-0002-8548-5240 NiBa department Understanding the evolution of continuous genomes project Identification of the genomic regions that contribute to reproductive isolation and how they interact is a major goal of evolutionary genetics. Much effort has focused on locating candidate genes and potential barrier loci by scanning genomes for regions of excess differentiation (FST). An alternative, and perhaps more robust approach, is to scan for genomic regions exhibiting steep clines in allele frequency across a hybrid zone. We develop a computationally efficient method for approximating cline parameters for large number of loci, and apply it to genomic data from across a hybrid zone between flower colour varieties of Antirrhinum majus (A. m. m var. pseudomajus and A. m. m var. striatum). Most steep clines are clustered in seven genomic regions, only four of which were present from FST scans between all pair-wise comparisons. Six of these regions carry previously identified loci that influence flower colour in the hybrid zone. The seventh region harbours a novel locus, RUBIA, modifying magenta intensity. Clines at RUBIA approached fixation on the magenta side of the hybrid zone, whilst remaining polymorphic on the yellow side. This polymorphism on the yellow side may reflect a smaller phenotypic effect of RUBIA in yellow compared to magenta genetic backgrounds. Our findings illustrate how whole-genome cline scans in hybrid zones can robustly detect genomic regions contributing to phenotypic differences and highlight how different reproductive barrier loci interact across the genome. https://research-explorer.ista.ac.at/download/22674/22683/2026_PloSGenetics_Field.pdf application/pdfno Public Library of Science2026 eng 1553-7404 4244162610.1371/journal.pgen.1012173 227 Field, David, et al. “Genome-Wide Cline Analysis Identifies New Locus Contributing to a Barrier to Gene Flow across an Antirrhinum Hybrid Zone.” <i>PLOS Genetics</i>, vol. 22, no. 7, e1012173, Public Library of Science, 2026, doi:<a href="https://doi.org/10.1371/journal.pgen.1012173">10.1371/journal.pgen.1012173</a>. Field, David, Sean Stankowski, Taylor Reiter, Jitka Polechova, Desmond Bradley, Daniel M. Richardson, Annabel Whibley, et al. “Genome-Wide Cline Analysis Identifies New Locus Contributing to a Barrier to Gene Flow across an Antirrhinum Hybrid Zone.” <i>PLOS Genetics</i>. Public Library of Science, 2026. <a href="https://doi.org/10.1371/journal.pgen.1012173">https://doi.org/10.1371/journal.pgen.1012173</a>. Field, D., Stankowski, S., Reiter, T., Polechova, J., Bradley, D., Richardson, D. M., … Barton, N. H. (2026). Genome-wide cline analysis identifies new locus contributing to a barrier to gene flow across an Antirrhinum hybrid zone. <i>PLOS Genetics</i>. Public Library of Science. <a href="https://doi.org/10.1371/journal.pgen.1012173">https://doi.org/10.1371/journal.pgen.1012173</a> Field D, Stankowski S, Reiter T, et al. Genome-wide cline analysis identifies new locus contributing to a barrier to gene flow across an Antirrhinum hybrid zone. <i>PLOS Genetics</i>. 2026;22(7). doi:<a href="https://doi.org/10.1371/journal.pgen.1012173">10.1371/journal.pgen.1012173</a> Field D, Stankowski S, Reiter T, Polechova J, Bradley D, Richardson DM, Whibley A, Pal A, Shipilina D, Boell L, Pickup M, Xue Y, Coen E, Barton NH. 2026. Genome-wide cline analysis identifies new locus contributing to a barrier to gene flow across an Antirrhinum hybrid zone. PLOS Genetics. 22(7), e1012173. D. Field <i>et al.</i>, “Genome-wide cline analysis identifies new locus contributing to a barrier to gene flow across an Antirrhinum hybrid zone,” <i>PLOS Genetics</i>, vol. 22, no. 7. Public Library of Science, 2026. D. Field, S. Stankowski, T. Reiter, J. Polechova, D. Bradley, D.M. Richardson, A. Whibley, A. Pal, D. Shipilina, L. Boell, M. Pickup, Y. Xue, E. Coen, N.H. Barton, PLOS Genetics 22 (2026). 226742026-08-11T06:19:05Z2026-08-11T07:55:22Z