The bluetail transposon: evidence for independent cis-regulatory domains and domain boundaries in the bithorax complex.
An extremely large cis-regulatory region generates the parasegment-specific expression patterns of the homeotic genes in the bithorax complex. We present evidence supporting the idea that this cis-regulatory region is subdivided into independent cis-regulatory domains. We describe a Ubx-lacZ transposon which is inserted into one of these domains, iab-7. The PS12-specific pattern of LacZ expression from this reporter indicates that it is subject to the control of the iab-7 cis-regulatory domain, but is protected from the effects of adjacent regulatory domains. Protection on the proximal side appears to be provided by the Fab-7 boundary element. Deletion of this boundary results in the ectopic activation of iab-7 in PS11 (where the iab-6 cis-regulatory domain normally functions). We show that the Fab-7 boundary, like other boundaries, has an unusual chromatin structure.
Department of Zoology and Animal Biology, University of Geneva, Switzerland.
M
M
Galloni
H
H
Gyurkovics
P
P
Schedl
F
F
Karch
D000818:Animals; D002843:Chromatin / Q000737:chemistry; D004251:DNA Transposable Elements; D004331:Drosophila melanogaster; D007814:Larva; D009154:Mutation; D012333:RNA, Messenger / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid; D013909:Thorax / Q000196:embryology; D001616:beta-Galactosidase / Q000235:genetics
D002843:Chromatin; D004251:DNA Transposable Elements; D012333:RNA, Messenger; D001616:beta-Galactosidase