article published yes Jack Peter Kelly Bravo author 96aecfa5-8931-11ee-af30-aa6a5d6eee0e0000-0003-0456-0753 JaBr department Ancient viral warfare could be at the root of modern class 1 CRISPR bacterial defense systems AAAS2026 eng 0036-8075 1095-9203 4275215310.1126/science.ael0758 39368171187-1188 Bravo JPK. A viral origin for RNA-guided immunity. <i>Science</i>. 2026;393(6817):1187-1188. doi:<a href="https://doi.org/10.1126/science.ael0758">10.1126/science.ael0758</a> Bravo JPK. 2026. A viral origin for RNA-guided immunity. Science. 393(6817), 1187–1188. Bravo, J. P. K. (2026). A viral origin for RNA-guided immunity. <i>Science</i>. AAAS. <a href="https://doi.org/10.1126/science.ael0758">https://doi.org/10.1126/science.ael0758</a> J. P. K. Bravo, “A viral origin for RNA-guided immunity,” <i>Science</i>, vol. 393, no. 6817. AAAS, pp. 1187–1188, 2026. J.P.K. Bravo, Science 393 (2026) 1187–1188. Bravo, Jack Peter Kelly. “A Viral Origin for RNA-Guided Immunity.” <i>Science</i>, vol. 393, no. 6817, AAAS, 2026, pp. 1187–88, doi:<a href="https://doi.org/10.1126/science.ael0758">10.1126/science.ael0758</a>. Bravo, Jack Peter Kelly. “A Viral Origin for RNA-Guided Immunity.” <i>Science</i>. AAAS, 2026. <a href="https://doi.org/10.1126/science.ael0758">https://doi.org/10.1126/science.ael0758</a>. 230002026-09-27T22:01:52Z2026-10-07T08:10:18Z