TY - JOUR TI - Dynamic spreading of chromatin-mediated gene silencing and reactivation between neighboring genes in single cells AU - Lensch, Sarah AU - Herschl, Michael H AU - Ludwig, Connor H AU - Sinha, Joydeb AU - Hinks, Michaela M AU - Mukund, Adi AU - Fujimori, Taihei AU - Bintu, Lacramioara A2 - Davidson, Irwin A2 - Struhl, Kevin A2 - Davidson, Irwin A2 - Trono, Didier VL - 11 PY - 2022 DA - 2022/06/09 SP - e75115 C1 - eLife 2022;11:e75115 DO - 10.7554/eLife.75115 UR - https://doi.org/10.7554/eLife.75115 AB - In mammalian cells genes that are in close proximity can be transcriptionally coupled: silencing or activating one gene can affect its neighbors. Understanding these dynamics is important for natural processes, such as heterochromatin spreading during development and aging, and when designing synthetic gene regulation circuits. Here, we systematically dissect this process in single cells by recruiting and releasing repressive chromatin regulators at dual-gene synthetic reporters, and measuring how fast gene silencing and reactivation spread as a function of intergenic distance and configuration of insulator elements. We find that silencing by KRAB, associated with histone methylation, spreads between two genes within hours, with a time delay that increases with distance. This fast KRAB-mediated spreading is not blocked by the classical cHS4 insulators. Silencing by histone deacetylase HDAC4 of the upstream gene can also facilitate background silencing of the downstream gene by PRC2, but with a days-long delay that does not change with distance. This slower silencing can sometimes be stopped by insulators. Gene reactivation of neighboring genes is also coupled, with strong promoters and insulators determining the order of reactivation. Our data can be described by a model of multi-gene regulation that builds upon previous knowledge of heterochromatin spreading, where both gene silencing and gene reactivation can act at a distance, allowing for coordinated dynamics via chromatin regulator recruitment. KW - mammalian synthetic biology KW - epigenetics KW - spatial-temporal dynamics KW - chromatin regulation KW - gene expression KW - insulators JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -