The mcp element from the Drosophila melanogaster bithorax complex mediates long-distance regulatory interactions.
In the studies reported here, we have examined the properties of the Mcp element from the Drosophila melanogaster bithorax complex (BX-C). We have found that sequences from the Mcp region of BX-C have properties characteristic of Polycomb response elements (PREs), and that they silence adjacent reporters by a mechanism that requires trans-interactions between two copies of the transgene. However, Mcp trans-regulatory interactions have several novel features. In contrast to classical transvection, homolog pairing does not seem to be required. Thus, trans-regulatory interactions can be observed not only between Mcp transgenes inserted at the same site, but also between Mcp transgenes inserted at distant sites on the same chromosomal arm, or even on different arms. Trans-regulation can even be observed between transgenes inserted on different chromosomes. A small 800-bp Mcp sequence is sufficient to mediate these long-distance trans-regulatory interactions. This small fragment has little silencing activity on its own and must be combined with other Polycomb-Group-responsive elements to function as a "pairing-sensitive" silencer. Finally, this pairing element can also mediate long-distance interactions between enhancers and promoters, activating mini-white expression.
Muller
M
M
Department of Molecular Biology, Princeton University, Princeton, New Jersey 08540, USA.
Hagstrom
K
K
Gyurkovics
H
H
Pirrotta
V
V
Schedl
P
P
D000818:Animals; D030801:Animals, Genetically Modified; D004268:DNA-Binding Proteins / Q000235:genetics*; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics*; D051717:Fushi Tarazu Transcription Factors; D005786:Gene Expression Regulation; D018398:Homeodomain Proteins / Q000235:genetics*; D019476:Insect Proteins / Q000235:genetics*; D008957:Models, Genetic; D063150:Polycomb Repressive Complex 1; D012045:Regulatory Sequences, Nucleic Acid; D015183:Restriction Mapping; D014157:Transcription Factors
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D051717:Fushi Tarazu Transcription Factors; D018398:Homeodomain Proteins; D019476:Insect Proteins; C066770:Pc protein, Drosophila; D014157:Transcription Factors; C066177:Ubx protein, Drosophila; C497169:ftz protein, Drosophila; D063150:Polycomb Repressive Complex 1