共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
Accumulating evidence has suggested that epigenetic marks including DNA methylation,small RNA and histone modification may involve hybrid vigor in plants.However,knowledge about how epigenetic marks in hybrids regulate gene expression is still limited.Based on genome-wide DNA methylation landscapes of Arabidopsis thaliana Ler and C24 ecotypes and their reciprocal F1 hybrids which were obtained in our previous work,we analyzed allele-specific DNA methylation and distinguished cis-and trans-regulated DNA methylation in hybrids.Our study indicated that both cis-and trans-regulated DNA methylation played roles in hybrids,when cis-regulation played a major role in CG methylation and trans-regulation played major roles in CHG and CHH methylation.In addition,we observed correlations between trans-regulated DNA methylation and siRNA densities.Enriched siRNA regions were significantly concurrent with highly trans-regulated DNA methylation regions.Our results illustrated DNA methylation regulation patterns integrated with siRNAs in Arabidopsis hybrids,and shed light on understanding the mechanism of epigenetic reprogramming for hybrid vigor. 相似文献
3.
4.
5.
多倍体植物的表观遗传现象 总被引:4,自引:0,他引:4
表观遗传现象是指基因表达发生改变但不涉及DNA序列的变化, 它存在于许多植物的多倍体化过程中,而且能够在代与代之间传递。表观遗传变异包括基因沉默、DNA甲基化、核仁显性、休眠转座子激活和基因组印记等方面。这种现象可能是由于基因组间的相互作用直接诱发基因沉默或基因表达改变所致;也可能由DNA甲基化之外的组蛋白编码的改变引起;或者与甲基化不足、染色质重组或转座子激活等有关。表观遗传变异在提高基因表达的多样性,引起遗传学和细胞学上的二倍化,以及促进基因组间的相互协调等方面起着重要作用。文章综述了植物多倍体化过程中的表观遗传现象及其在多倍体植物基因组进化中的作用,并在此基础上提出了今后在这方面的研究途径。 相似文献
6.
7.
8.
9.
Teresa Morales-Ruiz María Victoria García-Ortiz Iván Devesa-Guerra Laura Raya-Ruiz Juan R. Tejedor Gustavo F. Bayón 《Epigenetics》2018,13(1):95-107
Patterns of DNA methylation, an important epigenetic modification involved in gene silencing and development, are disrupted in cancer cells. Understanding the functional significance of aberrant methylation in tumors remains challenging, due in part to the lack of suitable tools to actively modify methylation patterns. DNA demethylation caused by mammalian DNA methyltransferase inhibitors is transient and replication-dependent, whereas that induced by TET enzymes involves oxidized 5mC derivatives that perform poorly understood regulatory functions. Unlike animals, plants possess enzymes that directly excise unoxidized 5mC from DNA, allowing restoration of unmethylated C through base excision repair. Here, we show that expression of Arabidopsis 5mC DNA glycosylase DEMETER (DME) in colon cancer cells demethylates and reactivates hypermethylated silenced loci. Interestingly, DME expression causes genome-wide changes that include both DNA methylation losses and gains, and partially restores the methylation pattern observed in normal tissue. Furthermore, such methylome reprogramming is accompanied by altered cell cycle responses and increased sensibility to anti-tumor drugs, decreased ability to form colonospheres, and tumor growth impairment in vivo. Our study shows that it is possible to reprogram a human cancer DNA methylome by expression of a plant DNA demethylase. 相似文献
10.
Analysis of target sequences of DDM1s in Brassica rapa by MSAP 总被引:1,自引:0,他引:1
DNA methylation is an important epigenetic modification regulating gene expression and transposon silencing. Although epigenetic
regulation is involved in some agricultural traits, there has been relatively little research on epigenetic modifications
of genes in Brassica rapa, which includes many important vegetables. In B. rapa, orthologs of DDM1, a chromatin remodeling factor required for maintenance of DNA methylation, have been characterized and
DNA hypomethylated knock-down plants by RNAi (ddm1-RNAi plants) have been generated. In this study, we investigated differences of DNA methylation status at the genome-wide
level between a wild-type (WT) plant and a ddm1-RNAi plant by methylation-sensitive amplification polymorphism (MSAP) analysis. MSAP analysis detected changes of DNA methylation
of many repetitive sequences in the ddm1-RNAi plant. Search for body methylated regions in the WT plant revealed no difference in gene body methylation levels between
the WT plant and the ddm1-RNAi plant. These results indicate that repetitive sequences are preferentially methylated by DDM1 genes in B. rapa. 相似文献
11.
12.
丝状真菌粗糙脉孢菌是一种作为遗传学研究的经典模式生物.通过对粗糙脉孢菌5S rRNA基因的组成和在染色体上分布的研究,揭示了丝状真菌中存在的一种基因组防御机制——重复序列诱导的DNA点突变(RIP).通过对发生突变的5S rRNA假基因的研究还发现,粗糙脉孢菌中存在一种重要的表观遗传修饰——DNA甲基化,随后的深入研究使粗糙脉孢菌成为解析DNA甲基化机制的最重要模式生物之一.粗糙脉孢菌基因转化操作引起的营养生长阶段同源基因的沉默(quelling)是由RNAi途径调控的,同时该途径也是调控减数分裂过程中非配对DNA诱发的基因沉默(meiotic silencing)的关键.由于粗糙脉孢菌基因组简单,且存在与高等真核生物相同的DNA甲基化和多种组蛋白的修饰,使其成为今后深入研究组蛋白修饰与染色质重塑等表观遗传现象参与基因表达调控和基因组稳定性维持的重要模式生物之一. 相似文献
13.
14.
15.
16.
17.
同卵双胞胎来源于同一个受精卵,DNA序列基本一致,但在某些重要表型上如复杂疾病,并不完全一样。利用表型不一致的同卵双胞胎进行研究,能在遗传背景、母体效应、年龄性别效应等一致的基础上,深入研究分析复杂性状的表观调控机制。而DNA甲基化是最为稳定的一类表观遗传修饰。在人类中,利用同卵双胞胎对印记异常疾病、精神类疾病、自身免疫病及癌症等疾病的DNA甲基化调控研究已经揭示了多个致病基因,为研究疾病的表观调控以及表观遗传学药物的应用打下了基础。本文着重对同卵双胞胎DNA甲基化状态、DNA甲基化遗传力计算以及复杂性状DNA甲基化调控的研究应用及其进展展开综述,以期为复杂性状表观调控机制研究提供借鉴和参考。 相似文献
18.
DNA甲基化——肿瘤产生的一种表观遗传学机制 总被引:16,自引:4,他引:12
在人类基因组中,DNA甲基化是一种表观遗传修饰,它与肿瘤的发生关系密切。抑癌基因和DNA修复基因的高甲基化、重复序列DNA的低甲基化、某些印记基因的印记丢失与多种肿瘤的发生有关。目前研究发现,基因组中甲基化的水平不仅受DNA 甲基化转移酶(DNMT)的影响,还与组蛋白甲基化、叶酸摄入、RNA干扰等多种因素有关。DNA甲基化在基因转录过程中扮有重要角色,并与组蛋白修饰、染色质构型重塑共同参与转录调控。 相似文献
19.
Sofia J. van Moorsel Marc W. Schmid Niels C. A. M. Wagemaker Thomas van Gurp Bernhard Schmid Philippine Vergeer 《Molecular ecology》2019,28(17):4097-4117
In long‐term grassland experiments, positive biodiversity effects on plant productivity commonly increase with time. Subsequent glasshouse experiments showed that these strengthened positive biodiversity effects persist not only in the local environment but also when plants are transferred into a common environment. Thus, we hypothesized that community diversity had acted as a selective agent, resulting in the emergence of plant monoculture and mixture types with differing genetic composition. To test our hypothesis, we grew offspring from plants that were grown for eleven years in monoculture or mixture environments in a biodiversity experiment (Jena Experiment) under controlled glasshouse conditions in monocultures or two‐species mixtures. We used epiGBS, a genotyping‐by‐sequencing approach combined with bisulphite conversion, to provide integrative genetic and epigenetic (i.e., DNA methylation) data. We observed significant divergence in genetic and DNA methylation data according to selection history in three out of five perennial grassland species, namely Galium mollugo, Prunella vulgaris and Veronica chamaedrys, with DNA methylation differences mostly reflecting the genetic differences. In addition, current diversity levels in the glasshouse had weak effects on epigenetic variation. However, given the limited genome coverage of the reference‐free bisulphite method epiGBS, it remains unclear how much of the differences in DNA methylation was independent of underlying genetic differences. Our results thus suggest that selection of genetic variants, and possibly epigenetic variants, caused the rapid emergence of monoculture and mixture types within plant species in the Jena Experiment. 相似文献
20.
Falk Zakrzewski Veit Schubert Prisca Viehoever André E. Minoche Juliane C. Dohm Heinz Himmelbauer Bernd Weisshaar Thomas Schmidt 《The Plant journal : for cell and molecular biology》2014,78(6):937-950
Methylation of DNA is important for the epigenetic silencing of repetitive DNA in plant genomes. Knowledge about the cytosine methylation status of satellite DNAs, a major class of repetitive DNA, is scarce. One reason for this is that arrays of tandemly arranged sequences are usually collapsed in next‐generation sequencing assemblies. We applied strategies to overcome this limitation and quantified the level of cytosine methylation and its pattern in three satellite families of sugar beet (Beta vulgaris) which differ in their abundance, chromosomal localization and monomer size. We visualized methylation levels along pachytene chromosomes with respect to small satellite loci at maximum resolution using chromosome‐wide fluorescent in situ hybridization complemented with immunostaining and super‐resolution microscopy. Only reduced methylation of many satellite arrays was obtained. To investigate methylation at the nucleotide level we performed bisulfite sequencing of 1569 satellite sequences. We found that the level of methylation of cytosine strongly depends on the sequence context: cytosines in the CHH motif show lower methylation (44–52%), while CG and CHG motifs are more strongly methylated. This affects the overall methylation of satellite sequences because CHH occurs frequently while CG and CHG are rare or even absent in the satellite arrays investigated. Evidently, CHH is the major target for modulation of the cytosine methylation level of adjacent monomers within individual arrays and contributes to their epigenetic function. This strongly indicates that asymmetric cytosine methylation plays a role in the epigenetic modification of satellite repeats in plant genomes. 相似文献