Frontabdominal-7, Fab-7 PRE
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\Fab-7 using the Feature Mapper tool.
GBrowse - Visual display of RNA-Seq signalsView Dmel\Fab-7 in GBrowse 2
Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see GBrowse for alignment of the cDNAs and ESTs to the gene model.
For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.
Fab-7 and MCP-PRE appear to have two distinct roles; they regulate the expression of their flanking genes in cis, but they also mediate long-distance regulatory interactions with Hox genes in the Antennapedia complex.
Trl protein-binding sites are necessary but not sufficient for full Fab-7 enhancer-blocking activity. Distinct Trl protein-binding sites within the Fab-7 element are required for different enhancer-blocking activities at different stages of development.
A Fab-7 element is switched from a silenced to a mitotically heritable active state by an embryonic pulse of transcription. Activated Fab-7 enables transcription of a gene even after withdrawal of the primary transcription factor.
Fab-7 can be switched to an active or a silencing mode. Both epigenetically determined states can be transmitted to a fraction of progeny in the next generation through the female germline. This suggests that a protein-based cellular memory mechanism can be propogated through meiosis.
The Fab-7 region can be subdivided into a chromatin domain boundary and a Polycomb-response element.
Deletion of the Fab-7 element results in fusion of the iab-6 and iab-7 cis-regulatory domains into a single regulatory domain that inappropriately regulates Abd-B. This result suggests Fab-7 is a chromatin domain boundary within the context of the bithorax complex that normally functions to ensure the autonomous activity of the iab-6 and iab-7 cis-regulatory domains.
A specialised DNA element, Fab-7, is proposed to function as a boundary element that separates the iab-6 and iab-7 cis regulatory regions within the Abd-B domain of the BX-C. Studies suggest Fab-7 functions as an attenuator which weakens gene expression by reducing enhancer-promoter interactions. Fab-7 selectively blocks distal enhancers in an orientation-independent fashion and can function when far from either the distal enhancer or target promoter.
The role of Fab-7 as a boundary element may be restricted to particular tissues in which the homeotic genes are active.
Boundary elements in the bithorax complex, such as Fab-7 organize the parasegment specific cis-regulatory sub-regions into a series of autonomous domains, insulating each domain from the regulatory influences of the adjacent ones.
An insulating boundary element in the 'Fab7' region is characterized by an unusual chromatin structure.
Fab-7 and Mcp region chromatin structure contain distinct chromatin structures that display similarities to the scs and scs' structures of the Hsp70A locus, and are constitutive. Deletion analysis demonstrates that the DNA segment required for Fab-7 function contains 3 nuclease hypersensitive regions and that for Mcp function contains 1 major hypersensitive region and 3 minor nuclease hypersensitive regions.