Visualization of trans-homolog enhancer-promoter interactions at the Abd-B hox locus in the Drosophila embryo
Visualization of trans-homolog enhancer-promoter interactions at the Abd-B hox locus in the Drosophila embryo
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DOI：
10.1016/j.devcel.2004.11.001
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发表时间：
2004-12-01
影响因子：
11.8
通讯作者：
Levine, M
中科院分区：
文献类型：
--
作者：
Ronshaugen, M;Levine, M
Hox基因Abdominal-B（Abd-B）控制果蝇后腹节的形态发生。表达由一系列自身转录的3'增强子调节。RNA FISH用于可视化与发育中的胚胎中的Abd-B的编码和非编码区相关的新生转录物。共聚焦成像表明，远端增强子通常环到Abd-B启动子区域。令人惊讶的是，位于一条染色体上的增强子经常与位于另一个同源物上的Abd-B转录单位相关联。这些反式同源物相互作用可以被解释为一种被称为transvection的遗传现象的直接可视化，由此Abd-B中的某些突变可以被该基因的另一个拷贝反式拯救。3'侧翼区中的10 kb序列介导Abd-B等位基因的紧密配对，从而促进远端增强子的反式成环。这种反式同源相互作用可能是高等后生动物基因调控的一种常见机制。
The Hox gene Abdominal-B (Abd-B) controls the morphogenesis of posterior abdominal segments in Drosophila. Expression is regulated by a series of 3' enhancers that are themselves transcribed. RNA FISH was used to visualize nascent transcripts associated with coding and noncoding regions of Abd-B in developing embryos. Confocal imaging suggests that distal enhancers often loop to the Abd-B promoter region. Surprisingly, enhancers located on one chromosome frequently associate with the Abd-B transcription unit located on the other homolog. These trans-homolog interactions can be interpreted as the direct visualization of a genetic phenomenon known as transvection, whereby certain mutations in Abd-B can be rescued in trans by the other copy of the gene. A 10 kb sequence in the 3' flanking region mediates tight pairing of Abd-B alleles, thereby facilitating trans looping of distal enhancers. Such trans-homolog interactions might be a common mechanism of gene regulation in higher metazoans.