Characterization of the transvection mediating region of the abdominal-B locus in Drosophila.
Characterization of the transvection mediating region of the abdominal-B locus in Drosophila.
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发表时间：
1999-07
期刊：
影响因子：
4.6
通讯作者：
Jumin Zhou;Hilary L. Ashe;Christian Burks;Michael S. Levine
中科院分区：
文献类型：
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作者：
Jumin Zhou;Hilary L. Ashe;Christian Burks;Michael S. Levine
遗传学研究已经在果蝇的腹部-B(Abd-B)基因座中发现了一种不寻常的横移过程。在某些情况下，远端腹下(IAB)调控结构域即使转移到不同的染色体上，也会继续激活ABD-B启动子。横移取决于一个大约。10kb基因组DNA序列，称为转导介导区(TMR)，位于AbD-B转录单位的下游。在这里，我们报道了对这一地区的详细分析。将TMR的不同DNA片段插入到不同的P转化载体中。对转基因胚胎和成体中报告基因表达的分析发现，至少有三个顺式调控元件，包括两个增强子(IAB7和IAB8)和一个新的绝缘体DNA(Frontabar-8，Fab-8)。也有证据表明，一个多梳反应元件(PRE)与IAB8增强子相连，以及IAB-8结构域中的一个内部启动子，它转录IAB-7和IAB-8顺式调节DNA，包括FAB-8绝缘体。我们讨论了这些发现对于哺乳动物珠蛋白基因座中ABD-B转导和长程增强子-启动子相互作用的意义。
Genetic studies have identified an unusual transvection process in the Abdominal-B (Abd-B) locus of Drosophila. In some cases distal infraabdominal (iab) regulatory domains continue to activate the Abd-B promoter even when translocated onto different chromosomes. Transvection depends on an approx. 10 kb genomic DNA sequence, termed the transvection mediating region (tmr), located immediately downstream of the Abd-B transcription unit. Here we report a detailed analysis of this region. Different DNA fragments from the tmr were inserted into a variety of P-transformation vectors. Analyses of reporter gene expression in transgenic embryos and adults identify at least three cis-regulatory elements, including two enhancers (IAB7 and IAB8) and a new insulator DNA (Frontabdominal-8, Fab-8). Evidence is also presented for a Polycomb Response Element (PRE) linked to the IAB8 enhancer, and an internal promoter in the iab-8 domain, which transcribes the iab-7 and iab-8 cis-regulatory DNA, including the Fab-8 insulator. We discuss the significance of these findings with regard to Abd-B transvection and long-range enhancer-promoter interactions in mammalian globin loci.