博文
表观遗传学等位基因
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Epialleles via DNA methylation: consequences for plant evolution
相关概念:In plants, naturally occurring methylation of genes can affect the level of gene expression. Variation among individuals in the degree of methylation of a gene, termed epialleles, produces novel phenotypes that are heritable across generations.基因甲基化影响基因表达水平,进而影响表型.甲基化基因和未甲基化基因在DNA序列上,完全相同,但存在表观遗传学修饰的不同,甲基化是其中的一种形式.所以叫epiallele.
水稻的基因克隆过程中的真实例子:Analysis of neighboring genes revealed that the candidate 2.6-kb
region was upstream of Os08g0509600 (also predicted as LOC_Os08g39890 in the Rice Genome Annotation Project; see URLs and Fig. 1e), which encodes the plant-specific transcription factor.....Sequence analysis revealed that there was no difference in the coding region of OsSPL14 between Nipponbare and ST-12 plants.(精细定位的侯选基因,在编码区无多态性).但是:Quantitative RT-PCR analysis of OsSPL14 detected a difference in expression between Nipponbare and ST-12.通过遗传互补实验证明这个基因是表型控制基因.所以很自然的就想到了Heritable differences in gene expression not due to DNA sequence changes are defined as epigenetic alleles(如果不这样假设,没法解释结果).下面就得做实验来验证了:We considered whether heritable epigenetic marks in the endogenous OsSPL14 promoter may be related to different expression levels of OsSPL14(测试的是promoter). To test this, we performed bisulfite sequencing to compare DNA methylation levels of the 2.6-kb candidate region in Nipponbare and ST-12; overall, there was no significant difference in total DNA methylation in the region (Supplementary Fig. 7) However, methylation differences were observed at several cytosines near 1,070 base pairs, with higher levels of methylation in Nipponbare (68–79%) compared to ST-12 (0–24%) (Supplementary Fig. 8). (结果:总甲击化水平无显著差异,但个别地方的甲基化水平明显不同)These results warrant further investigation to determine if OsSPL14 is regulated by a heritable epigenetic mechanism in ST-12(所以,结论是:需要进一步的测试.他的测试结果也许会另外发篇文章).
region was upstream of Os08g0509600 (also predicted as LOC_Os08g39890 in the Rice Genome Annotation Project; see URLs and Fig. 1e), which encodes the plant-specific transcription factor.....Sequence analysis revealed that there was no difference in the coding region of OsSPL14 between Nipponbare and ST-12 plants.(精细定位的侯选基因,在编码区无多态性).但是:Quantitative RT-PCR analysis of OsSPL14 detected a difference in expression between Nipponbare and ST-12.通过遗传互补实验证明这个基因是表型控制基因.所以很自然的就想到了Heritable differences in gene expression not due to DNA sequence changes are defined as epigenetic alleles(如果不这样假设,没法解释结果).下面就得做实验来验证了:We considered whether heritable epigenetic marks in the endogenous OsSPL14 promoter may be related to different expression levels of OsSPL14(测试的是promoter). To test this, we performed bisulfite sequencing to compare DNA methylation levels of the 2.6-kb candidate region in Nipponbare and ST-12; overall, there was no significant difference in total DNA methylation in the region (Supplementary Fig. 7) However, methylation differences were observed at several cytosines near 1,070 base pairs, with higher levels of methylation in Nipponbare (68–79%) compared to ST-12 (0–24%) (Supplementary Fig. 8). (结果:总甲击化水平无显著差异,但个别地方的甲基化水平明显不同)These results warrant further investigation to determine if OsSPL14 is regulated by a heritable epigenetic mechanism in ST-12(所以,结论是:需要进一步的测试.他的测试结果也许会另外发篇文章).
这个例子在这篇文章中:OsSPL14 promotes panicle branching and higher grain productivity in rice
OsSPL14 promotes panicle branching and higher grain productivity in rice 2010.pdf
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另一种表观遗传学修饰:Trimethylation of histone H3 lysine 27 (H3K27me3).参见
Whole-Genome Analysis of Histone H3 Lysine 27 Trimethylation in Arabidopsis
https://blog.sciencenet.cn/blog-479743-503729.html
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