Wildwater Marjolein, Campilho Ana, Perez-Perez Jose Manuel, Heidstra Renze, Blilou Ikram, Korthout Henrie, Chatterjee Jayanta, Mariconti Luisa, Gruissem Wilhelm, Scheres Ben
Department of Molecular Cell Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
Cell. 2005 Dec 29;123(7):1337-49. doi: 10.1016/j.cell.2005.09.042.
The maintenance of stem cells in defined locations is crucial for all multicellular organisms. Although intrinsic factors and signals for stem cell fate have been identified in several species, it has remained unclear how these connect to the ability to reenter the cell cycle that is one of the defining properties of stem cells. We show that local reduction of expression of the RETINOBLASTOMA-RELATED (RBR) gene in Arabidopsis roots increases the amount of stem cells without affecting cell cycle duration in mitotically active cells. Conversely, induced RBR overexpression dissipates stem cells prior to arresting other mitotic cells. Overexpression of D cyclins, KIP-related proteins, and E2F factors also affects root stem cell pool size, and genetic interactions suggest that these factors function in a canonical RBR pathway to regulate somatic stem cells. Expression analysis and genetic interactions position RBR-mediated regulation of the stem cell state downstream of the patterning gene SCARECROW.
干细胞在特定位置的维持对所有多细胞生物都至关重要。尽管在多个物种中已鉴定出干细胞命运的内在因素和信号，但这些因素如何与重新进入细胞周期的能力相关联仍不清楚，而重新进入细胞周期是干细胞的定义特性之一。我们发现，拟南芥根中视网膜母细胞瘤相关（RBR）基因表达的局部降低会增加干细胞数量，而不影响有丝分裂活跃细胞的细胞周期持续时间。相反，诱导RBR过表达会在阻止其他有丝分裂细胞之前使干细胞耗散。D型细胞周期蛋白、KIP相关蛋白和E2F因子的过表达也会影响根干细胞库的大小，遗传相互作用表明这些因子在经典的RBR途径中发挥作用以调节体细胞干细胞。表达分析和遗传相互作用将RBR介导的干细胞状态调节定位在模式基因稻草人下游。
