Methylation and expression of amplified esterase genes in the aphid Myzus persicae (Sulzer)
Methylation and expression of amplified esterase genes in the aphid Myzus persicae (Sulzer)
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DOI：
10.1042/bj3490863
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发表时间：
2000-08-01
影响因子：
4.1
通讯作者：
Field, LM
中科院分区：
文献类型：
--
作者：
Field, LM
大多数种群的蚜虫桃蚜有扩增的基因（高达80个拷贝）编码的E4酯酶。本文报告了甲基化敏感的限制性内切酶，CpG分析和亚硫酸氢盐测序的E4基因及其侧翼DNA的甲基化分析。综合起来，这些表明E4的5-甲基胞嘧啶局限于CpG双联体，正如之前在脊椎动物基因组中所显示的那样;这是关于昆虫基因的首次此类报道。甲基化存在于基因内，但不存在于上游区域，包括转录起始周围的5'CpG富集区和3'侧翼DNA。甲基化的E4基因表达; 5-甲基胞嘧啶的损失与转录的损失相关，尽管这并不伴随着蚜虫基因组中存在的5-甲基胞嘧啶的整体损失。这些结果表明，E4的甲基化在表达中具有积极作用，并质疑广泛持有的观点，即无脊椎动物基因组中的甲基化仅限于不含基因的区域，甲基化总是与基因沉默相关。
Most populations of the aphid Myzus persicae have amplified genes (up to 80 copies) encoding the insecticide-detoxifying esterase E4. This paper reports the analysis of methylation of the E4 gene and its flanking DNA with the use of methylation-sensitive restriction enzymes, CpG profiling and bisulphite sequencing. In combination these show that E4 has 5-methyl-cytosine confined to CpG doublets, as previously shown for vertebrate genomes; this is the first such report for an insect gene. The methylation is present within the gene but absent from upstream regions, including the 5' CpG-rich region around the start of transcription, and from 3' flanking DNA. Methylated E4 genes are expressed; loss of the 5-methylcytosine is correlated with a loss of transcription, although this is not accompanied by a global loss of the 5-methylcytosine present in the aphid genome. These results suggest that the methylation of E4 has a positive role in expression, and call into question the widely held view that methylation in invertebrate genomes is confined to regions that do not contain genes and that methylation is always associated with gene silencing.