Hn. Cai et al., LONG-RANGE REPRESSION IN THE DROSOPHILA EMBRYO, Proceedings of the National Academy of Sciences of the United Statesof America, 93(18), 1996, pp. 9309-9314
Transcriptional repressors can be characterized by their range of acti
on on promoters and enhancers. Short-range repressors interact over di
stances of 50-150 bp to inhibit, or quench, either upstream activators
or the basal transcription complex. In contrast, long-range repressor
s act over several kilobases to silence basal promoters. We describe r
ecent progress in characterizing the functional properties of one such
long-range element in the Drosophila embryo and discuss the contrasti
ng types of gene regulation that are made possible by short- and long-
range repressors.