Expression dynamics of WOX genes mark cell fate decisions during early embryonic patterning in Arabidopsis thaliana
Expression dynamics of WOX genes mark cell fate decisions during early embryonic patterning in Arabidopsis thaliana
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DOI：
10.1242/dev.00963
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发表时间：
2004-02-01
期刊：
影响因子：
4.6
通讯作者：
Laux, T
中科院分区：
文献类型：
--
作者：
Haecker, A;Gross-Hardt, R;Laux, T
在胚胎模式形成过程中，建立了主体轴，并从单细胞受精卵中指定了不同发育命运的细胞。尽管这一过程很重要，但在植物中，潜在的机制在很大程度上是未知的。我们发现WOX(WUSCHEL Related Homeobox)基因家族新成员的表达动态揭示了拟南芥早期的胚胎模式事件。WOX2和WOX8在卵细胞和受精卵中共表达，并通过不对称分裂分别局限于受精卵顶端和基底层的子细胞。WOX2不仅标志着受精卵的顶端后代，而且在功能上也是其正常发育所必需的，这表明植物受精卵的不对称分裂分离了顶端和基底细胞命运的决定因素。WOX9的表达在受精卵的基底层子细胞中启动，随后转移到顶端子代，显然是对来自胚胎本身的信号的响应。WOX5的表达表明，静止中心的识别在脑垂体细胞中很早就开始了，并突出了根和茎分生组织干细胞生态位之间的分子和发育相似之处。综上所述，我们的数据表明，在植物胚胎发生过程中，单个前体细胞很早就启动了区域特异性转录程序，而WOX基因在这一过程中发挥了重要作用。
During embryonic pattern formation, the main body axes are established and cells of different developmental fates are specified from a single-cell zygote. Despite the fundamental importance of this process, in plants, the underlying mechanisms are largely unknown. We show that expression dynamics of novel WOX (WUSCHEL related homeobox) gene family members reveal early embryonic patterning events in Arabidopsis. WOX2 and WOX8 are coexpressed in the egg cell and zygote and become confined to the apical and basal daughter cells of the zygote, respectively, by its asymmetric division. WOX2 not only marks apical descendants of the zygote, but is also functionally required for their correct development, suggesting that the asymmetric division of the plant zygote separates determinants of apical and basal cell fates. WOX9 expression is initiated in the basal daughter cell of the zygote and subsequently shifts into the descendants of the apical daughter apparently in response to signaling from the embryo proper. Expression of WOX5 shows that identity of the,quiescent center is initiated very early in the hypophyseal cell, and highlights molecular and developmental similarities between the stem cell niches of root and shoot meristems. Together, our data suggest that during plant embryogenesis region-specific transcription programs are initiated very early in single precursor cells and that WOX genes play an important role in this process.