Fz1, Dfz1, DFz, frz, Frizzled 1
Gene model reviewed during 5.44
Stop-codon suppression (UAG) postulated; FBrf0216884.
Transposon inserted in intron
Low-frequency RNA-Seq exon junction(s) not annotated.
Gene model reviewed during 5.46
Gene model reviewed during 5.53
None of the polypeptides share 100% sequence identity.
Experiments with heat shock driven transgenes demonstrate that only the longer 581aa form of the fz protein shows any activity and rescues fz mutations. Overexpression results in two distinct tissue polarity phenotypes.
The fz protein contains and odd number of transmembrane domains and is glycosylated.
One of a couple of protein products.
Interacts with ATP6AP2.
Lys-Thr-X-X-X-Trp motif interacts with the PDZ domain of Dvl (Disheveled) family members and is involved in the activation of the Wnt/beta-catenin signaling pathway.
The FZ domain is involved in binding with Wnt ligands.
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\fz using the Feature Mapper tool.
GBrowse - Visual display of RNA-Seq signalsView Dmel\fz in GBrowse 2
Please Note FlyBase no longer curates genomic clone accessions so this list may not be complete
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.
Source for identity of: fz CG3646
Source for merge of: fz CG3646 CG17697
Most alleles fit into a hypomorphic to amorphic series with many hemizygotes displaying a more severe phenotype than homozygotes.
Mutations in fz influence the arrangement of ommatidia at the micro-scale but have no effect on the ommatidium nano-scale structure.
fz is required for normal salivary gland migration in the embryo. It is required in the second phase of salivary gland migration, as the gland moves posteriorly within the embryo.
Clonal analysis indicates that the ds/ft system and the stan/fz system act independently to confer planar cell polarity in the adult abdomen; each system confers and propagates polarity and can do so in the absence of the other.
dsRNA made from templates generated with primers directed against this gene.
fz is transported to the distal sides of developing wing blade cells during pupal stages by transport in microtubules associated endosomes.
Molecular analyses suggest that the cysteine-rich domain of fz recruits wg, and bound wg interacts with the membrane portion of the receptor to initiate signalling. RNAi knockdown experiments show that fz and wg also require the receptor Arr1 to initiate arm signalling.
dsRNA made from templates generated with primers directed against this gene tested in RNAi screen for effects on Kc167 and S2R+ cell morphology.
The fz feedback loop, acting to propagate polarity from cell to cell, is sufficient to align planar polarity of cells in the wing.
in and fy are needed in cells receiving and responding to a fz dependent intercellular signal. Genetic analysis is not consistent with fz-like class of genes fz, pk, Vang, stan and dsh acting simply as positive or negative regulators of in and fy.
Mutations in fz-like class of genes fz, pk, Vang, stan and dsh act as strong enhancers of weak in or fy phenotypes. In the wing as in the abdomen in and fy are epistatic to fz as double mutants resemble in and fy and not fz. fz and Vang show complementary domineering nonautonomy in the wing and abdomen. The domineering nonautonomy in the abdomen of fz clones is not blocked by cells also being mutant for in. In the eye fz is epistatic to in and fy. In terms of the wing eversion phenotype of fz, in and fy appear to be epistatic to fz.
fz participates in the pIIa vs pIIb fate decision in the external sensory organ lineage.
Area matching Drosophila Frizzled gene Acc. No. X54648.
the asymmetric localisation of fz in adult wing cells may be an instructive cue in the determination of cell polarity.
fz-mediated signalling provides polarity information to pI, specifying the orientation of mitotic spindles. The orientations of the pIIa and pIIb divisions are independent of fz signalling and are instead defined by the axis of the previous pI division.
Cells can assess the level of fz protein on neighbouring cells and use this as a source of polarity information.
Mutants do not exhibit defects in the denticle belt of hairs of the larvae.
Planar polarity phenotypes of loss of function and overexpression of fz in the developing eye is studied, the phenotype is almost identical to loss of function or overexpression of dsh, or overexpression of sgg. Overexpression of fz in the developing eye has a potent polarizing effect on the retinal epithelium.
Cell nonautonomous fz alleles are associated with mutations that alter amino acids in all regions of the encoded protein. The four cell autonomous mutations fall in a proline residue in the presumptive first cytoplasmic loop of the protein. Comparison of fz with Dvir\fz revealed that the protein is unusually well conserved: in the putative cytoplasmic domains the two proteins are identical.
Loss of fz function affects the rotation and breaking of symmetry of photoreceptor cell preclusters. Clonal analysis reveals that fz acts non-autonomously. Mitotic clones affect the polarity of neighboring wild-type ommatidia distal, but not proximal to the equatorial midline, suggesting that fz might mediate a signal in the developing eye transmitted bidirectionally from the equator to the opposite poles.
The function of fz is required in the establishment of mirror-image symmetry about the equatorial midline in the compound eye.
Mutant phenotype suggests fz is required for the correct rotational direction, the precise 90o turn and the correct asymmetry arrangement of R3 and R4 cells. fz is not required for the synchronous movement of photoreceptor cells within individual clusters since photoreceptor cells in each fz mutant ommatidium still rotate as a unit. Mosaic analysis demonstrates fz has non-autonomous effects on eye development. Double mutant analysis suggests that nmo and fz functional synergistically in directing ommatidial rotation.
A cold sensitive allele of fz has been isolated and study of the mutant argues that fz has a regulatory function in specifying where the prehair forms, but has no role in the actual morphogenesis of the prehair.
Western blot analysis of fz protein accumulation in wing discs and pupal wings demonstrates fz is expressed in all regions of the epidermis before, during and after the fz cold sensitive period and prehair morphogenesis. fz function is not required for normal fz expression and mutations in other tissue polarity genes does not alter the amount or size of fz protein.
fz protein is an integral membrane protein with an odd number of transmembrane domains. Immunostaining of pupal wings reveals that the fz protein is evenly distributed across the wing and concentrates in the apical region of the pupal wing cells.
Two similar proteins identified in rat.
Cloning and characterisation of the fz locus has shown that this locus is very large (over 90kb) and probably encodes an integral membrane protein.
Hairs on thorax directed irregularly toward midline. Thoracic bristles also inturned and often wavy. Postverticals may turn outward. Hairs on wing edge and feet nearly erect; trichomes on wings of flies carrying weaker alleles tend to form swirls rather than lying parallel to one another and pointing distally; stronger alleles can cause random orientation of trichomes. Polarity of chaetae deranged in characteristic ways on wings, notum, halteres, legs, tergites and sternites; fz M+ clones in M/+ wings cause derangement of polarity in M/+ cells surrounding clone (Gubb and Garcia-Bellido, 1982). In a wild-type background clones of wing cells homozygous for fz alleles that cause eye roughening, but not of those without effect on eye texture, cause adjacent normal trichomes in regions distal, anterior and posterior, but not proximal to the clone, to orient toward the clone rather than distally as they normally do; no effect on trichomes on opposite surface of the wing (Vinson and Adler, 1987). Wing may be reduced. A low level of doubling of trichomes and splitting of chaetae observed. Sex combs may be irregular. Most alleles cause eyes to be rough Extra leg joints tend to form as mirror-image duplications proximal to the normal joints on tarsal segments one to four. Also polarities of bristles, hairs, and bracts on legs abnormal (Held, Duarte and Derakhshanian, 1986).
Bridges, 18th Feb. 1938.