Orr-Weaver T L, Johnston C G, Spradling A C
Whitehead Institute for Biomedical Research, MIT, Nine Cambridge Center, MA 02142.
EMBO J. 1989 Dec 20;8(13):4153-62. doi: 10.1002/j.1460-2075.1989.tb08600.x.
ACE3, an amplification control element for the third chromosome chorion cluster of Drosophila melanogaster, was identified previously as a cis-regulatory element for amplification of transposons containing the three chorion genes s18, s15 and s19. The deletion defining ACE3, located from -620 to -190 bp upstream of s18, disrupted both amplification and s18 transcription, suggesting that ACE3 might contain a transcription enhancer that regulated replication, as had been observed in a number of eukaryotic viruses. We show here that transcription control can be separated from replication control in delineating ACE3 to a 320 bp region. Addition of heterologous enhancers fails to activate amplification in tissues other than the follicle cells. Therefore ACE3 does not appear to be analogous to a transcription enhancer. However, further deletions within the ACE3 region revealed that it contains multiple functional domains. In addition, ACE3 functions independently of orientation with respect to other chorion sequences, and can be moved 1.5 kb away from other chorion sequences without eliminating amplification.
ACE3是黑腹果蝇第三号染色体绒毛膜基因簇的一个扩增控制元件，先前被鉴定为包含三个绒毛膜基因s18、s15和s19的转座子扩增的顺式调控元件。界定ACE3的缺失位于s18上游-620至-190 bp处，破坏了扩增和s18转录，这表明ACE3可能含有一个调控复制的转录增强子，正如在许多真核病毒中所观察到的那样。我们在此表明，在将ACE3界定到一个320 bp区域时，转录控制可以与复制控制分离。添加异源增强子不能在卵泡细胞以外的组织中激活扩增。因此，ACE3似乎与转录增强子不同。然而，ACE3区域内的进一步缺失表明它包含多个功能域。此外，ACE3的功能独立于相对于其他绒毛膜序列的方向，并且可以从其他绒毛膜序列移开1.5 kb而不消除扩增。
