Zhang Hong-Yu, Xu Pei-Zhou, Yang Hua, Wu Xian-Jun
Rice Research Institute of Sichuan Agricultural University, Wenjiang 611130, China.
Yi Chuan. 2010 Jul;32(7):670-6. doi: 10.3724/sp.j.1005.2010.00670.
Genomic imprinting refers to the phenomenon that the expression of a gene copy depends on its parent of origin. The Arabidopsis imprinted FIS (Fertilisation-independent seed) genes, mea, fis2, and fie, play essential roles in the repression of central cell and the regulation of early endosperm development. fis mutants display two phenotypes: autonomous diploid endosperm development when fertilization is absent and un-cellularised endosperm formation when fertilization occurs. The FIS Polycomb protein complex including the above three FIS proteins catalyzes histone H3 K27 tri-methylation on target loci. DME (DEMETER), a DNA glycosylase, and AtMET1 (Methyltransferase1), a DNA methyltransferase, are involved in the regulation of imprinted expression of both mea and fis2. This review summarizes the studies on the Arabidopsis imprinted FIS genes and other related genes. Recent works have shown that the insertion of transposons may affect nearby gene expression, which may be the main driving force behind the evolution of genomic imprinting. This summary covers the achievements on Arabidopsis imprinted genes will provide important information for studies on genomic imprinting in the important crops such as rice and maize.
基因组印记是指基因拷贝的表达取决于其亲本来源的现象。拟南芥中印记的FIS（非受精种子）基因，MEA、FIS2和FIE，在中央细胞的抑制和早期胚乳发育的调控中起重要作用。FIS突变体表现出两种表型：受精缺失时自主的二倍体胚乳发育，以及受精时未细胞化的胚乳形成。包括上述三种FIS蛋白的FIS多梳蛋白复合体催化靶位点上组蛋白H3 K27三甲基化。DNA糖基化酶DME（脱氨酶）和DNA甲基转移酶AtMET1（甲基转移酶1）参与MEA和FIS2印记表达的调控。本综述总结了对拟南芥印记FIS基因及其他相关基因的研究。最近的研究表明，转座子的插入可能影响附近基因的表达，这可能是基因组印记进化背后的主要驱动力。本综述涵盖了拟南芥印记基因的研究成果，将为水稻和玉米等重要作物的基因组印记研究提供重要信息。
