article published yes Christian A. Ibarra author Xiaoqi Feng author Vera K. Schoft author Tzung-Fu Hsieh author Rie Uzawa author Jessica A. Rodrigues author Assaf Zemach author Nina Chumak author Adriana Machlicova author Toshiro Nishimura author Denisse Rojas author Robert L. Fischer author Hisashi Tamaru author Daniel Zilberman author 6973db13-dd5f-11ea-814e-b3e5455e9ed10000-0002-0123-8649 DaZi department The Arabidopsis thaliana central cell, the companion cell of the egg, undergoes DNA demethylation before fertilization, but the targeting preferences, mechanism, and biological significance of this process remain unclear. Here, we show that active DNA demethylation mediated by the DEMETER DNA glycosylase accounts for all of the demethylation in the central cell and preferentially targets small, AT-rich, and nucleosome-depleted euchromatic transposable elements. The vegetative cell, the companion cell of sperm, also undergoes DEMETER-dependent demethylation of similar sequences, and lack of DEMETER in vegetative cells causes reduced small RNA–directed DNA methylation of transposons in sperm. Our results demonstrate that demethylation in companion cells reinforces transposon methylation in plant gametes and likely contributes to stable silencing of transposable elements across generations. American Association for the Advancement of Science2012 eng 0036-8075 1095-9203 2298407410.1126/science.1224839 33761001360-1364 yes Ibarra, Christian A., Xiaoqi Feng, Vera K. Schoft, Tzung-Fu Hsieh, Rie Uzawa, Jessica A. Rodrigues, Assaf Zemach, et al. “Active DNA Demethylation in Plant Companion Cells Reinforces Transposon Methylation in Gametes.” <i>Science</i>. American Association for the Advancement of Science, 2012. <a href="https://doi.org/10.1126/science.1224839">https://doi.org/10.1126/science.1224839</a>. Ibarra, C. A., Feng, X., Schoft, V. K., Hsieh, T.-F., Uzawa, R., Rodrigues, J. A., … Zilberman, D. (2012). Active DNA demethylation in plant companion cells reinforces transposon methylation in gametes. <i>Science</i>. American Association for the Advancement of Science. <a href="https://doi.org/10.1126/science.1224839">https://doi.org/10.1126/science.1224839</a> Ibarra, Christian A., et al. “Active DNA Demethylation in Plant Companion Cells Reinforces Transposon Methylation in Gametes.” <i>Science</i>, vol. 337, no. 6100, American Association for the Advancement of Science, 2012, pp. 1360–64, doi:<a href="https://doi.org/10.1126/science.1224839">10.1126/science.1224839</a>. C. A. Ibarra <i>et al.</i>, “Active DNA demethylation in plant companion cells reinforces transposon methylation in gametes,” <i>Science</i>, vol. 337, no. 6100. American Association for the Advancement of Science, pp. 1360–1364, 2012. Ibarra CA, Feng X, Schoft VK, Hsieh T-F, Uzawa R, Rodrigues JA, Zemach A, Chumak N, Machlicova A, Nishimura T, Rojas D, Fischer RL, Tamaru H, Zilberman D. 2012. Active DNA demethylation in plant companion cells reinforces transposon methylation in gametes. Science. 337(6100), 1360–1364. C.A. Ibarra, X. Feng, V.K. Schoft, T.-F. Hsieh, R. Uzawa, J.A. Rodrigues, A. Zemach, N. Chumak, A. Machlicova, T. Nishimura, D. Rojas, R.L. Fischer, H. Tamaru, D. Zilberman, Science 337 (2012) 1360–1364. Ibarra CA, Feng X, Schoft VK, et al. Active DNA demethylation in plant companion cells reinforces transposon methylation in gametes. <i>Science</i>. 2012;337(6100):1360-1364. doi:<a href="https://doi.org/10.1126/science.1224839">10.1126/science.1224839</a> 94512021-06-04T07:51:31Z2021-12-14T08:28:51Z