Mutations in the FIE and MEA Genes That Encode Interacting Polycomb Proteins Cause Parent-of-Origin Effects on Seed Development by Distinct Mechanisms
Mutations in the FIE and MEA Genes That Encode Interacting Polycomb Proteins Cause Parent-of-Origin Effects on Seed Development by Distinct Mechanisms
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DOI：
10.1105/tpc.12.12.2367
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发表时间：
2000-12
期刊：
影响因子：
11.6
通讯作者：
R. Yadegari;T. Kinoshita;O. Lotan;G. Cohen;A. Katz;Yeonhee Choi;A. Katz;K. Nakashima;J. Harada-J.-H
中科院分区：
文献类型：
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作者：
R. Yadegari;T. Kinoshita;O. Lotan;G. Cohen;A. Katz;Yeonhee Choi;A. Katz;K. Nakashima;J. Harada-J.-H
在开花植物中，两个细胞在单倍体雌性配子体中受精。卵子和精子核融合形成胚胎。第二个精子核与中心细胞核融合，中心细胞核复制产生胚乳，胚乳是支持胚胎发育的组织。受精非依赖性胚乳（FIE）和MEDEA （MEA）基因分别编码WD和SET结构域多梳蛋白。在没有受精的情况下，一个失去功能的5或1等位基因的雌性配子体在没有受精的情况下启动胚乳发育。5和mea突变也引起亲本起源效应，其中野生型母本等位基因对种子的生存至关重要，父本等位基因则是可有可无的。本研究表明，FIE和MEA多梳蛋白在物理上相互作用，表明WD和SET结构域多梳蛋白的分子伙伴关系在开花植物的进化过程中得到了保守。FIE和MEA的重叠表达模式与它们在中央细胞中抑制基因转录和胚乳发育以及在受精后控制种子发育一致。尽管FIE和MEA相互作用，但母体和父本表达模式的差异，以及DNA甲基化1基因减少（DDM1）隐性突变对突变等位基因传播的影响表明，FIE和MEA突变通过不同的机制导致亲本起源对种子发育的影响。
In flowering plants, two cells are fertilized in the haploid female gametophyte. Egg and sperm nuclei fuse to form the embryo. A second sperm nucleus fuses with the central cell nucleus, which replicates to generate the endosperm, a tissue that supports embryo development. The FERTILIZATION-INDEPENDENT ENDOSPERM (FIE) and MEDEA (MEA) genes encode WD and SET domain polycomb proteins, respectively. In the absence of fertilization, a female gametophyte with a loss-of-function fie or mea allele initiates endosperm development without fertilization. fie and mea mutations also cause parent-of-origin effects, in which the wild-type maternal allele is essential and the paternal allele is dispensable for seed viability. Here, we show that FIE and MEA polycomb proteins interact physically, suggesting that the molecular partnership of WD and SET domain polycomb proteins has been conserved during the evolution of flowering plants. The overlapping expression patterns of FIE and MEA are consistent with their suppression of gene transcription and endosperm development in the central cell as well as their control of seed development after fertilization. Although FIE and MEA interact, differences in maternal versus paternal patterns of expression, as well as the effect of a recessive mutation in the DECREASE IN DNA METHYLATION1 (DDM1) gene on mutant allele transmission, indicate that fie and mea mutations cause parent-of-origin effects on seed development by distinct mechanisms.