Ohad N, Yadegari R, Margossian L, Hannon M, Michaeli D, Harada J J, Goldberg R B, Fischer R L
Department of Plant Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
Plant Cell. 1999 Mar;11(3):407-16. doi: 10.1105/tpc.11.3.407.
A fundamental problem in biology is to understand how fertilization initiates reproductive development. Higher plant reproduction is unique because two fertilization events are required for sexual reproduction. First, a sperm must fuse with the egg to form an embryo. A second sperm must then fuse with the adjacent central cell nucleus that replicates to form an endosperm, which is the support tissue required for embryo and/or seedling development. Here, we report cloning of the Arabidopsis FERTILIZATION-INDEPENDENT ENDOSPERM (FIE) gene. The FIE protein is a homolog of the WD motif-containing Polycomb proteins from Drosophila and mammals. These proteins function as repressors of homeotic genes. A female gametophyte with a loss-of-function allele of fie undergoes replication of the central cell nucleus and initiates endosperm development without fertilization. These results suggest that the FIE Polycomb protein functions to suppress a critical aspect of early plant reproduction, namely, endosperm development, until fertilization occurs.
生物学中的一个基本问题是了解受精如何启动生殖发育。高等植物的繁殖是独特的，因为有性生殖需要两个受精事件。首先，一个精子必须与卵子融合形成胚胎。然后，第二个精子必须与相邻的中央细胞核融合，该核复制形成胚乳，胚乳是胚胎和/或幼苗发育所需的支持组织。在这里，我们报告了拟南芥自主胚乳（FIE）基因的克隆。FIE蛋白是果蝇和哺乳动物中含WD基序的多梳蛋白的同源物。这些蛋白作为同源异型基因的抑制因子发挥作用。具有fie功能缺失等位基因的雌配子体经历中央细胞核的复制，并在未受精的情况下启动胚乳发育。这些结果表明，FIE多梳蛋白的功能是抑制植物早期繁殖的一个关键方面，即胚乳发育，直到受精发生。
