Pérez-Lluch Sílvia, Cuartero Sergi, Azorín Fernando, Espinàs M Lluïsa
Institut de Biologia Molecular de Barcelona, CSIC, Institut de Recerca Biomedica de Barcelona, IRBB, Parc Científic de Barcelona, Barcelona, Spain.
Nucleic Acids Res. 2008 Dec;36(21):6926-33. doi: 10.1093/nar/gkn818. Epub 2008 Oct 31.
The homeotic Abdominal-B (Abd-B) gene expression depends on a modular cis-regulatory region divided into discrete functional domains (iab) that control the expression of the gene in a particular segment of the fly. These domains contain regulatory elements implicated in both initiation and maintenance of homeotic gene expression and elements that separate the different domains. In this paper we have performed an extensive analysis of the iab-6 regulatory region, which regulates Abd-B expression at abdominal segment A6 (PS11), and we have characterized two new polycomb response elements (PREs) within this domain. We report that PREs at Abd-B cis-regulatory domains present a particular chromatin structure which is nuclease accessible all along Drosophila development and both in active and repressed states. We also show that one of these regions contains a dCTCF and CP190 dependent activity in transgenic enhancer-blocking assays, suggesting that it corresponds to the Fab-6 boundary element of the Drosophila bithorax complex.
同源异型基因腹部B（Abd - B）的表达依赖于一个模块化的顺式调控区域，该区域被划分为离散的功能结构域（iab），这些结构域控制着该基因在果蝇特定节段中的表达。这些结构域包含与同源异型基因表达的起始和维持相关的调控元件，以及分隔不同结构域的元件。在本文中，我们对iab - 6调控区域进行了广泛分析，该区域在腹部A6节段（PS11）调控Abd - B的表达，并且我们在这个结构域内鉴定出了两个新的多梳反应元件（PRE）。我们报告称，Abd - B顺式调控结构域中的PRE呈现出一种特殊的染色质结构，在果蝇发育的整个过程中以及在激活和抑制状态下均对核酸酶可及。我们还表明，在转基因增强子阻断试验中，这些区域之一含有一种依赖于dCTCF和CP190的活性，这表明它对应于果蝇双胸复合体的Fab - 6边界元件。
