Department of Developmental Biology, Biocenter Klein Flottbek, University of Hamburg, Hamburg, Germany.
Department of Molecular Mechanisms of Phenotypic Plasticity, Institut de Biologie Moléculaire des Plantes du Centre National de la Recherche Scientifique, Université de Strasbourg, Strasbourg, France.
Science. 2017 Apr 28;356(6336). doi: 10.1126/science.aaf6532.
To produce seeds, flowering plants need to specify somatic cells to undergo meiosis. Here, we reveal a regulatory cascade that controls the entry into meiosis starting with a group of redundantly acting cyclin-dependent kinase (CDK) inhibitors of the KIP-RELATED PROTEIN (KRP) class. KRPs function by restricting CDKA;1-dependent inactivation of the Retinoblastoma homolog RBR1. In and triple mutants, designated meiocytes undergo several mitotic divisions, resulting in the formation of supernumerary meiocytes that give rise to multiple reproductive units per future seed. One function of RBR1 is the direct repression of the stem cell factor (), which ectopically accumulates in meiocytes of triple and mutants. Depleting in mutants restored the formation of only a single meiocyte.
为了产生种子，开花植物需要指定体细胞进行减数分裂。在这里，我们揭示了一个调控级联，它从一组冗余作用的细胞周期蛋白依赖性激酶（CDK）抑制剂 KIP-RELATED PROTEIN（KRP）家族开始，控制进入减数分裂。KRPs 通过限制 CDKA；1 依赖性失活的视网膜母细胞瘤同源物 RBR1。在 和 三突变体中，指定的减数分裂细胞经历几次有丝分裂分裂，导致超数减数分裂细胞的形成，每个未来的种子产生多个生殖单位。RBR1 的一个功能是直接抑制干细胞因子 ()，它在三突变体的减数分裂细胞中异位积累。在 突变体中耗尽 仅恢复了单个减数分裂细胞的形成。
