Do differentially regulated regions (DMRs) control imprinting of the maize fie1 and fie2 genes?

差异调节区 (DMR) 是否控制玉米 fie1 和 fie2 基因的印记？

• 批准号: BB/E008585/1
• 负责人: Hugh Dickinson
• 金额: $ 56.35万
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2007
• 资助国家: 英国
• 起止时间: 2007 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FE008585%2F1
• 关键词: Do; differentially; regulated; regions; DMRs

Many aspects of early development in plants and animals are controlled by systems of genetic imprinting by which, for a particular gene, either the maternal or the paternal copy (allele) is silenced. Importantly, imprinting in plants affects only the endosperm - one of the two structures (the other being the embryo) formed following double fertilisation. The endosperm can be regarded as analogous to the yolk of an animal egg, providing nutrients to the developing embryo. Importantly the endosperm forms the bulk of the grain of all cereals, and its correct development (and improvement) is thus of great commercial and sociological significance. Recent work on plants, some in the applicant's laboratory, has shown - again as in animals - that expression of imprinted alleles is regulated by chemical modifications to the DNA in the form of methylation. We have now shown that this methylation differs in the maternal and paternal alleles of an important pair of developmental genes in maize (fie1 and fie2), and that, surprisingly, this methylation behaves in different ways in these two genes, suggesting that their imprinting is regulated by differing mechanisms. Interestingly, for one gene (fie1) the paternal copy is methylated in the gametes, while the paternal copy of fie2 is only becomes methylated after fertilisation. The small amount of data from plants suggest that methylation is directlty associated with gene silencing, but this is not the case in animals where it forms only one component of a complex process by which modifications are made both to the DNA and to associated proteins in regions termed DMRs (Differentially Methylated Regions). We now want to dissect this regulatory pathway in plants, first by determining whether it is the methylation itself that silences gene expression, and then by exploring the possibility that the DMRs in plants are marked, prior to DNA methylation, by modified versions of histones, and other proteins which form part of the chromosome matrix (the chromatin). For this work we shall use mutant lines of plants incapable of carrying out methylation, or modifying histones, and a number of well-tried transgenic approaches to investigate changes at the level of individual DMRs. Finally we shall use a recently-developed chromatin-immunoprecipitation system (ChIP) to identify the proteins associated with the DMRs, and to discover whether one group of these proteins, the Polycomb Group, regulate both themselves and imprinting.

植物和动物早期发育的许多方面都是由遗传印记系统控制的，通过这种系统，对于一个特定的基因，母系或父系的拷贝（等位基因）是沉默的。重要的是，植物的印记只影响胚乳——两种结构中的一种（另一种是胚胎）在双重受精后形成。胚乳可以看作类似于动物卵子的蛋黄，为发育中的胚胎提供营养。重要的是，胚乳构成了所有谷物的大部分，因此它的正确发展（和改进）具有重大的商业和社会学意义。最近对植物的研究（其中一些是在申请人的实验室进行的）再次表明，与动物一样，印迹等位基因的表达是由甲基化形式的DNA化学修饰来调节的。我们现在已经证明，这种甲基化在玉米的一对重要发育基因（fie1和fie2）的母系和父系等位基因中是不同的，而且，令人惊讶的是，这种甲基化在这两个基因中以不同的方式表现，这表明它们的印记是由不同的机制调节的。有趣的是，一个基因（fie1）的父本拷贝在配子中被甲基化，而fie2的父本拷贝只在受精后才被甲基化。来自植物的少量数据表明，甲基化与基因沉默直接相关，但在动物中情况并非如此，甲基化只是一个复杂过程的一个组成部分，通过这个过程，DNA和DMRs（差异甲基化区）区域的相关蛋白质都发生了修饰。我们现在想要剖析植物中的这种调控途径，首先要确定甲基化本身是否使基因表达沉默，然后探索植物中的DMRs在DNA甲基化之前被修饰过的组蛋白和其他组成染色体基质（染色质）的蛋白质标记的可能性。在这项工作中，我们将使用不能进行甲基化或修饰组蛋白的植物突变系，以及一些经过验证的转基因方法来研究个体DMRs水平的变化。最后，我们将使用最近开发的染色质免疫沉淀系统（ChIP）来鉴定与DMRs相关的蛋白质，并发现这些蛋白质中的一组Polycomb group是否同时调节自身和印迹。

项目成果

When genomes collide: aberrant seed development following maize interploidy crosses.

• DOI: 10.1093/aob/mcn017
• 发表时间: 2008-04
• 期刊: Annals of botany
• 影响因子: 4.2
• 作者: Paul D Pennington;Liliana M. Costa;J. Gutierrez-Marcos;A. Greenland;H. Dickinson

And baby makes three: genomic imprinting in plant embryos.

• DOI: 10.1371/journal.pgen.1003981
• 发表时间: 2013
• 期刊: PLoS genetics
• 影响因子: 4.5
• 作者: Dickinson H;Scholten S
• 通讯作者: Scholten S

Maternal Control of Nutrient Allocation in Plant Seeds by Genomic Imprinting

• DOI: 10.1016/j.cub.2012.10.012
• 发表时间: 2012-10
• 期刊: Current Biology
• 影响因子: 9.2
• 作者: Liliana M. Costa;Jing Yuan;J. Rouster;W. Paul;H. Dickinson;J. Gutierrez-Marcos