绝缘子在果蝇体内启动子靶向性序列(PTS)中的功能研究

Requirement of Insulator for The Functions of Promoter Targeting Sequence in vivo of Drosophila Bithorax

在复杂基因组中,绝缘子形成了染色质区域的边界,阻止邻近的基因上的增强子对这些启动子进行不必要的激活。果蝇双胸复合体的Abd-B基因区域的启动子靶向序列(promoter targeting sequence,PTS)能够克服一个绝缘子的作用,并且推动和限制单个启动子的作用。研究发现这个启动子靶向序列活性的建立需要一个绝缘子对它进行激活,但是无需这个绝缘子存在就可以持续下去。这些结果表明启动子靶向序列的建立是不依赖于增强子活性的,是通过发育和后代繁衍的表观遗传保持下去的。

In complex genomes, insulators set up chromatin domain boundaries, and protect promoters from unwanted activation by enhancers from neighboring genes. The Promoter Targeting Sequence （PTS） from the Abdominal-B locus of the Drosophila Bithorax complex overcomes an insulator, and facilitates, but restricts, distant enhancers to a single promoter. Experiments showed that this promoter targeting activity required an insulator for its establishment, but could be maintained by the PTS in the absence of an insulator. These results sequence suggest that PTS is established independently of enhancer activity and is maintained epigenetically throughout development and subsequent generations.