Suppr超能文献

音猬因子(Shh)与ZRS增强子的共定位特定于极化活性区。

Shh and ZRS enhancer colocalisation is specific to the zone of polarising activity.

作者信息

Williamson Iain, Lettice Laura A, Hill Robert E, Bickmore Wendy A

机构信息

MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, Crewe Road, Edinburgh EH4 2XU, UK.

MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, Crewe Road, Edinburgh EH4 2XU, UK

出版信息

Development. 2016 Aug 15;143(16):2994-3001. doi: 10.1242/dev.139188. Epub 2016 Jul 11.

Abstract

Limb-specific Shh expression is regulated by the (∼1 Mb distant) ZRS enhancer. In the mouse, limb bud-restricted spatiotemporal Shh expression occurs from ∼E10 to E11.5 at the distal posterior margin and is essential for correct autopod formation. Here, we have analysed the higher-order chromatin conformation of Shh in expressing and non-expressing tissues, both by fluorescence in situ hybridisation (FISH) and by chromosome conformation capture (5C). Conventional and super-resolution light microscopy identified significantly elevated frequencies of Shh/ZRS colocalisation only in the Shh-expressing regions of the limb bud, in a conformation consistent with enhancer-promoter loop formation. However, in all tissues and at all developmental stages analysed, Shh-ZRS spatial distances were still consistently shorter than those to a neural enhancer located between Shh and ZRS in the genome. 5C identified a topologically associating domain (TAD) over the Shh/ZRS genomic region and enriched interactions between Shh and ZRS throughout E11.5 embryos. Shh/ZRS colocalisation, therefore, correlates with the spatiotemporal domain of limb bud-specific Shh expression, but close Shh and ZRS proximity in the nucleus occurs regardless of whether the gene or enhancer is active. We suggest that this constrained chromatin configuration optimises the opportunity for the active enhancer to locate and instigate the expression of Shh.

摘要

肢体特异性的音猬因子(Shh)表达受(约1兆碱基远处的)ZRS增强子调控。在小鼠中,肢体芽中受限制的时空性Shh表达在约胚胎第10天到11.5天于远端后缘出现,且对于正确的手部形成至关重要。在此,我们通过荧光原位杂交(FISH)和染色体构象捕获(5C)技术分析了Shh在表达和非表达组织中的高阶染色质构象。传统和超分辨率光学显微镜仅在肢体芽的Shh表达区域发现Shh/ZRS共定位频率显著升高,其构象与增强子-启动子环的形成一致。然而,在所有分析的组织和发育阶段,Shh与ZRS的空间距离始终比其与基因组中位于Shh和ZRS之间的神经增强子的距离短。5C技术确定了Shh/ZRS基因组区域上的一个拓扑相关结构域(TAD),并在整个胚胎第11.5天期间富集了Shh与ZRS之间的相互作用。因此,Shh/ZRS共定位与肢体芽特异性Shh表达的时空结构域相关,但无论基因或增强子是否活跃,Shh和ZRS在细胞核中都紧密相邻。我们认为这种受限的染色质构型优化了活性增强子定位并启动Shh表达的机会。

https://cdn.ncbi.nlm.nih.gov/pmc/blobs/74b1/5004883/741cafd14d34/develop-143-139188-g1.jpg

文献AI研究员

20分钟写一篇综述,助力文献阅读效率提升50倍。

立即体验

用中文搜PubMed

大模型驱动的PubMed中文搜索引擎

马上搜索

文档翻译

学术文献翻译模型,支持多种主流文档格式。

立即体验