Polyploidy and haploid are widely employed in the studies of genetics and evolution, and great pro-gress has been made in these fields, inspiring the enthusiasm of scientists to explore the ploidy effects in gene expression. In this paper, we review the gene expression and its regulation in polyploids, es-pecially in autopolyploids. We summarize some limitations in previous reports on polyploidy gene ex-pression and its regulation, especially the limitations in the research materials. We propose an idea to create homologous ploidy series with twin-seedlings and to employ high-throughput techniques to investigate the polyploidy transcriptome and its regulation.
PENG Hai1, ZHANG Jing1 & WU XianJun2,3 1 Laboratory of Germplasm and Genetics, College of Life Science, Jianghan University, Wuhan 430056, China
基因组印记是指后代仅表达亲本之一基因拷贝的现象。印记基因的发生是防止孤雌生殖发生的有效手段之一。拟南芥FIS(Fertilisation-independent seed)印记基因mea、fis2和fie在中央细胞分裂抑制和早期胚乳发育调节中发挥重要作用。fis突变体具有两种表型:当受精缺失时二倍体胚乳自主发育,而当受精发生时形成非细胞化的胚乳。FIS多梳蛋白复合体(Polycomb protein complex)包括上述3种FIS蛋白,在目标位点催化组蛋白H3第27位赖氨酸的tri-甲基化(H3K27 tri-methylation)。DME(DEMETER)和AtMET1(Methyltransferase1)参与了mea和fis2的印记表达控制。最近研究结果表明,开花植物中转座子的插入影响邻近基因的表达,是基因组印记进化的主要驱动力量。本文综述了10年来拟南芥中FIS印记基因和相关基因的发现及其调控机理,期望能为水稻、玉米等重要作物中印记基因的研究提供借鉴和参考。
In this study, microarray technique was employed to analyze the gene expression at the RNA level between haploids and corresponding diploids derived from a rice twin-seedling line SARII-628. Differ- ent degrees of expression variations were observed in the plant after haploidization. The main results are as follows: (1) after haploidization, the ratio of the sensitive loci was 2.47% of the total loci designed on chip. Those loci were randomly distributed on the 12 pairs of rice chromosomes and the activated loci were more than the silenced ones. (2) Gene clusters on chromosome were observed for 33 se- quences. (3) GoPipe function classification for 575 sensitive loci revealed an involvement in the bio- logical process, cell component and molecular function. (4) RT-PCR generally validated the result from microarray with a coincidence rate of 83.78%. And for the randomly-selected activated or silenced loci in chip analysis, the coincidence rate was up to 91.86%.
