SLOW WALKER2, a NOC1/MAK21 Homologue, Is Essential for Coordinated Cell Cycle Progression during Female Gametophyte Development in Arabidopsis
SLOW WALKER2, a NOC1/MAK21 Homologue, Is Essential for Coordinated Cell Cycle Progression during Female Gametophyte Development in Arabidopsis
复制标题
SLOW WALKER2 是一种 NOC1/MAK21 同源物，对于拟南芥雌性配子体发育期间协调细胞周期进展至关重要
DOI：
10.1104/pp.109.142414
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发表时间：
2009-11-01
期刊：
影响因子：
7.4
通讯作者：
Yang, Wei-Cai
中科院分区：
文献类型：
--
作者：
Li, Na;Yuan, Li;Yang, Wei-Cai
形态发生需要细胞生长、分裂和分化的协调。开花植物的雌性配子体发生是指单个单倍体孢子在细胞化前经过连续生长和核分裂而不发生胞质分裂，形成一个八核共胞胚囊，这为研究多细胞生物这一过程的遗传控制提供了一个很好的系统。本文报道了一种拟南芥（Arabidopsis thaliana）雌性配子体突变体slow walker2 （swa2）的特征，该突变体有丝分裂周期的进展和雌性配子体发育的同步性受到损害，导致雌性配子体在二核、四核或八核阶段停滞。延迟授粉试验表明，部分突变胚珠能够发育成功能胚囊，并能受精。SWA2编码一种与酵母核仁复合物相关蛋白1 (NOC1)/ KILLER21同源的核仁蛋白，该蛋白与NOC2一起参与核仁前体从细胞核向细胞质的输出。同样，SWA2也可以与拟南芥NOC2同源物相互作用。SWA2在整个植物中普遍表达，在积极分裂的组织和配子体中表达水平很高。因此，我们得出结论，SWA2很可能在核糖体生物发生中发挥作用，这对雌性配子体的协调有丝分裂进程至关重要。
Morphogenesis requires the coordination of cell growth, division, and cell differentiation. Female gametogenesis in flowering plants, where a single haploid spore undergoes continuous growth and nuclear division without cytokinesis to form an eight-nucleate coenocytic embryo sac before cellularization, provides a good system to study the genetic control of such processes in multicellular organisms. Here, we report the characterization of an Arabidopsis (Arabidopsis thaliana) female gametophyte mutant, slow walker2 (swa2), in which the progression of the mitotic cycles and the synchrony of female gametophyte development were impaired, causing an arrest of female gametophytes at the two-, four-, or eight-nucleate stage. Delayed pollination test showed that a portion of the mutant ovules were able to develop into functional embryo sacs and could be fertilized. SWA2 encodes a nucleolar protein homologous to yeast NUCLEOLAR COMPLEX ASSOCIATED PROTEIN1 (NOC1)/MAINTENANCE OF KILLER21 that, together with NOC2, is involved in preribosome export from the nucleus to the cytoplasm. Similarly, SWA2 can physically interact with a putative Arabidopsis NOC2 homologue. SWA2 is expressed ubiquitously throughout the plant, at high levels in actively dividing tissues and gametophytes. Therefore, we conclude that SWA2 most likely plays a role in ribosome biogenesis that is essential for the coordinated mitotic progression of the female gametophyte.