Identification of gametophytic mutations affecting female gametophyte development in Arabidopsis
Identification of gametophytic mutations affecting female gametophyte development in Arabidopsis
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DOI：
10.1006/dbio.1998.8980
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发表时间：
1998-10-01
影响因子：
2.7
通讯作者：
Drews, GN
中科院分区：
文献类型：
--
作者：
Christensen, CA;Subramanian, S;Drews, GN
雌配子体(胚囊或大配子体)在被子植物有性繁殖中起着至关重要的作用。正是这种结构产生了卵细胞和中央细胞，中央细胞在受精后分别形成种子的胚胎和胚乳。此外，雌配子体还参与许多生殖过程，包括花粉管引导、受精和种子发育的诱导。在大配子发生过程中发生了几个重大事件，包括合体核分裂、细胞化、核迁移和融合以及细胞死亡。虽然这些事件在形态上已经被描述，但在雌配子体中调节它们的分子在很大程度上是未知的。我们讨论了一种基于种子减少和分离扭曲的遗传筛选，以确定影响大配子发生和雌配子体功能的突变。我们报告了四个突变(Fem1，Fem2，Fem3和Fem4)的分离，并表明这四个突变映射到基因组中的不同位置。此外，我们发现Fem1和Fem2突变只影响雌配子体，而Fem3和Fem4突变同时影响雌配子体和雄配子体。我们分析了这四个突变体以及gfa2、gfa3、gfa4、gfa5和gfa7突变体的雌配子体发育。我们发现，Fem2、Fem3、gfa4和gfa5突变体在单核阶段中止发育，而Fem1、Fem4、gfa5、gfa3和gfa7突变体在发育后期受到影响，如极核融合和细胞化。建立鉴定突变的遗传筛选和开发快速分析突变表型的程序，是分离调控雌配子体发育和功能的分子的第一步。(C)1998年学术出版社。
The female gametophyte (embryo sac or megagametophyte) plays a critical role in sexual reproduction of angiosperms. It is the structure that produces the egg cell and central cell which, following fertilization, give rise to the seed's embryo and endosperm, respectively. In addition, the female gametophyte mediates a host of reproductive processes including pollen tube guidance, fertilization, and the induction of seed development. Several major events occur during megagametogenesis, including syncitial nuclear divisions, cellularization, nuclear migration and fusion, and cell death. While these events have been described morphologically, the molecules regulating them in the female gametophyte are largely unknown. We discuss a genetic screen based on reduced seed set and segregation distortion to identify mutations affecting megagametogenesis and female gametophyte function. We report on the isolation of four mutants (fem1, fem2 fem3, and fem4) and show that the four mutations map to different locations within the genome. Additionally, we show that the fem1 and fem2 mutations affect only the female gametophyte, while the fem3 and fem4 mutations affect both the female and male gametophyte. We analyzed female gametophyte development in these four mutants as well as in the gfa2, gfa3, gfa4, gfa5, and gfa7 mutants. We found that the fem2 fem3, gfa4 and gfa5 mutants abort development at the one-nucleate stage, while the fem1, fem4, gfa5 gfa3, and gfa7 mutants are affected in processes later in development such as polar nuclei fusion and cellularization. The establishment of a genetic screen to identify mutants and the development of a rapid procedure for analyzing mutant phenotypes represent a first step in the isolation of molecules that regulate female gametophyte development and function. (C) 1998 Academic Press.