High-resolution Micro-C maps identified a specialized class of regulatory DNAs termed ‘tethering elements’ (TEs) in Drosophila. These 300–500-bp elements facilitate specific long-range genomic associations or loops. The POZ-containing transcription factor GAF (GAGA-associated factor) contributes to loop formation. Tether–tether interactions accelerate Hox gene activation by distal enhancers, and coordinate transcription of duplicated genes (paralogs) through promoter–promoter associations. Some TEs engage in ultra-long-range enhancer–promoter and promoter–promoter interactions (meta-loops) in the Drosophila brain. We discuss the basis for tether–tether specificity and speculate on the occurrence of similar elements in vertebrate genomes.

高分辨率 Micro-C 图谱鉴定了果蝇中一类特殊的调控 DNA，称为“束缚元件”(TE) 。这些 300-500 bp 的元件促进特定的长范围基因组关联或环。含有 POZ 的转录因子 GAF（GAGA 相关因子）有助于环的形成。系链-系链相互作用通过远端增强子加速 Hox 基因的激活，并通过启动子-启动子关联协调重复基因（旁系同源物）的转录。一些 TE 在果蝇大脑中参与超长程增强子-启动子和启动子-启动子相互作用（元环）。我们讨论了系链特异性的基础，并推测脊椎动物基因组中相似元件的出现。