Identification of genes expressed in the Arabidopsis female gametophyte
Identification of genes expressed in the Arabidopsis female gametophyte
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DOI：
10.1111/j.1365-313x.2007.03137.x
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发表时间：
2007-07-01
期刊：
影响因子：
7.2
通讯作者：
Drews, Gary N.
中科院分区：
文献类型：
--
作者：
Steffen, Joshua G.;Kang, Il-Ho;Drews, Gary N.
被子植物雌配子体通常由一个卵细胞、两个助细胞、一个中央细胞和三个反足细胞组成。这四种细胞类型中的每一种都有独特的结构特征，并执行着对生殖过程至关重要的独特功能。赋予这四种表型状态的基因调控网络在很大程度上是未知的。作为解剖雌配子体基因调控网络的第一步，我们已经鉴定了在拟南芥雌配子体特定细胞中表达的大量基因。我们在缺乏雌配子体的决定基因不育1(Dif1)胚珠中的表达减少的基础上，使用差异表达筛选来鉴定这些基因。我们将胚珠RNA探针与Affymetrix ATH1基因组阵列杂交，并使用实时RT-PCR验证所识别的基因。这些检测确定了71个在dif1胚珠中表达降低的基因。我们进一步利用启动子：：GFP融合验证了这些基因中的45个，其中43个在雌配子体中表达。在胚珠中，11个基因在反足细胞中表达，11个基因在中央细胞中特异或优势表达，17个基因在助细胞中特异或优势表达，1个基因在卵细胞中特异表达，3个基因在雌配子体的多个细胞中强烈表达。这些基因提供了对雌配子体功能的分子过程的洞察，并可以作为切入点来剖析在四种雌配子体细胞分化过程中发挥作用的基因调控网络。
The angiosperm female gametophyte typically consists of one egg cell, two synergid cells, one central cell, and three antipodal cells. Each of these four cell types has unique structural features and performs unique functions that are essential for the reproductive process. The gene regulatory networks conferring these four phenotypic states are largely uncharacterized. As a first step towards dissecting the gene regulatory networks of the female gametophyte, we have identified a large collection of genes expressed in specific cells of the Arabidopsis thaliana female gametophyte. We identified these genes using a differential expression screen based on reduced expression in determinant infertile1 (dif1) ovules, which lack female gametophytes. We hybridized ovule RNA probes with Affymetrix ATH1 genome arrays and validated the identified genes using real-time RT-PCR. These assays identified 71 genes exhibiting reduced expression in dif1 ovules. We further validated 45 of these genes using promoter::GFP fusions and 43 were expressed in the female gametophyte. In the context of the ovule, 11 genes were expressed exclusively in the antipodal cells, 11 genes were expressed exclusively or predominantly in the central cell, 17 genes were expressed exclusively or predominantly in the synergid cells, one gene was expressed exclusively in the egg cell, and three genes were expressed strongly in multiple cells of the female gametophyte. These genes provide insights into the molecular processes functioning in the female gametophyte and can be used as starting points to dissect the gene regulatory networks functioning during differentiation of the four female gametophyte cell types.