Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom;
Genes Dev. 2013 Sep 1;27(17):1845-50. doi: 10.1101/gad.221713.113.
Vernalization, the promotion of flowering by cold, involves Polycomb-mediated epigenetic silencing of FLOWERING LOCUS C (FLC). Cold progressively promotes cell-autonomous switching to a silenced state. Here, we used live-cell imaging of FLC-lacO to monitor changes in nuclear organization during vernalization. FLC-lacO alleles physically cluster during the cold and generally remain so after plants are returned to warm. Clustering is dependent on the Polycomb trans-factors necessary for establishment of the FLC silenced state but not on LIKE HETEROCHROMATIN PROTEIN 1, which functions to maintain silencing. These data support the view that physical clustering may be a common feature of Polycomb-mediated epigenetic switching mechanisms.
春化作用，即低温促进开花，涉及多梳介导的开花位点 C（FLC）的表观遗传沉默。低温逐渐促进细胞自主向沉默状态转变。在这里，我们使用 FLC-lacO 的活细胞成像来监测春化过程中核组织的变化。FLC-lacO 等位基因在寒冷时会发生物理聚集，并且在植物返回温暖环境后通常仍然保持聚集状态。这种聚集依赖于建立 FLC 沉默状态所需的多梳转录因子，但不依赖于同源异型盒蛋白 1（LHP1），LHP1 是维持沉默所必需的。这些数据支持这样一种观点，即物理聚类可能是多梳介导的表观遗传开关机制的共同特征。
