Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, India.
Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, India.
Genomics. 2019 Mar;111(2):177-185. doi: 10.1016/j.ygeno.2018.02.001. Epub 2018 Feb 10.
Heterochromatin is associated with transcriptional repression. In contrast, several genes in the pericentromeric regions of Drosophila melanogaster are dependent on this heterochromatic environment for their expression. Here we present a comprehensive analysis of the epigenetic landscape of heterochromatic genes across all the developmental stages of Drosophila using the available histone modification and expression data from modENCODE. We find that heterochromatic genes exhibit combinations of active and inactive histone marks that correspond to their level of expression during development. We also show that Nuclear Matrix Associated Regions (MARs) are prominently present in the intergenic regions of heterochromatic genes during embryonic stages suggesting their plausible role in pericentromeric genome organization. Taken together, our meta-analysis of the various genomic datasets suggest that the epigenomic and genomic landscape of the heterochromatic genes are distinct which could be contributing to their unusual regulatory features as opposed to the surrounding heterochromatin, which is repressive in nature.
异染色质与转录抑制有关。相比之下，果蝇着丝粒区域的几个基因依赖于这种异染色质环境来表达。在这里，我们使用 modENCODE 提供的现有组蛋白修饰和表达数据，对果蝇所有发育阶段的异染色质基因的表观遗传景观进行了全面分析。我们发现，异染色质基因表现出与发育过程中表达水平相对应的活性和非活性组蛋白标记的组合。我们还表明，MARs（核基质相关区域）在胚胎阶段异染色质基因的基因间区域中大量存在，这表明它们在着丝粒基因组组织中的可能作用。总之，我们对各种基因组数据集的元分析表明，异染色质基因的表观基因组和基因组景观是不同的，这可能有助于它们作为不同于周围抑制性异染色质的不寻常调控特征，而周围异染色质是抑制性的。
