ROLE OF CYTOSINE METHYLATION IN C. CINEREUS

胞嘧啶甲基化在 C. Cinereus 中的作用

• 批准号: 6104550
• 负责人: SYLVIA A FRAZIER-BOWERS
• 金额: --
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-07-01 至 2000-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6104550
• 关键词: ROLE; CYTOSINE; METHYLATION; C.; CINEREUS

Examining the Role of Cytosine Methylation in Coprinus cinereus CpG methylation is known to be involved in gene silencing and to be responsible for genomic imprinting and X-chromosome inactivation. This work addresses the consequences of cytosine methylation in the fungal system Coprinus cinereus and currently is studying the location and extent of 5-methyl cytosine (m5C) residues in the tryptophan synthetase gene (trpi). The genomic sequencing protocol has been refined to study methylation in our fungal system. In the critical reaction of this protocol, cytosine is deaminated to uracil upon treatment with sodium bisulfite while m5C remains unchanged. Thus, the presence of m5C residues is indicated by the remaining cytosines in the sequence data. Analysis of six tetrads with both Trp+ and Trp- progeny allowed me to make a direct comparison of differences in methylation between silenced and unsilenced genes. Sequence analysis of all DNAs proved that cytosine methylation occurs mostly at the CpG dinucleotide as in mammalian systems, and that Trp- DNA has a larger amount of methylated cytosines as compared to Trp+ DNA. Further analysis will determine if there is site specificity for cytosine methylation and if specific methylated cytosines are necessary and sufficient to render the trp1 gene inactive. C. cinereus has proven to be a model system for studying methylation and may give us clues about how gene silencing occurs in this species and possibly in eukaryotes as a whole. This may lead to a better understanding of the role of m5C in controlling gene expression and further elucidate its role in diseases such as cancer and the Fragile-X syndrome.

检查胞嘧啶甲基化在Coprinus cinereus中的作用 CpG甲基化已知与基因沉默有关， 负责基因组印迹和X染色体灭活。 这 工作解决了真菌中胞嘧啶甲基化的后果 系统cinereus，目前正在研究该位置和 色氨酸合成酶中5-甲基胞嘧啶（M5C）残基的范围 基因（TRPI）。 基因组测序方案已被完善以研究 我们的真菌系统中的甲基化。 在此关键反应中 方案，钠治疗后，胞嘧啶会脱氨 Bisulfite时M5C保持不变。 因此，M5C的存在 残基在序列数据中的其余细胞固体表示。 分析六个具有TRP+和TRP-后代的四四甲板，使我得以 直接比较沉默的甲基化差异 和未灌输的基因。 所有DNA的序列分析证明了 胞嘧啶甲基化主要发生在CpG二核苷酸 哺乳动物系统，该TRP-DNA具有更大量的甲基化 与TRP+ DNA相比，胞嘧啶。 进一步的分析将确定是否 有胞质甲基化的位点特异性，如果具体 甲基化的胞嘧啶是必要的，足以使TRP1呈现 基因无活性。 C. Cinereus已被证明是研究的模型系统 甲基化，可能会为我们提供有关基因沉默如何发生的线索 该物种以及整个真核生物。 这可能会导致 更好地理解M5C在控制基因表达中的作用 并进一步阐明其在癌症和疾病中的作用 脆弱-X综合征。