Role of the Drosophila patched gene in positional signalling

  title={Role of the Drosophila patched gene in positional signalling},
  author={Philip W. Ingham and A. Malcolm R. Taylor and Yoshiro Nakano},
AFTER cellularization of the Drosophila embryo, positional differences within each primordial segment are maintained and elaborated by processes that require cell interactions. The best-documented examples1,2 of such intercellular signalling are the mutual interactions between neighbouring cells expressing the homeodomain protein engrailed3 and the secreted glycoprotein encoded by wingless4, the Drosophila homologue of the murine Wnt-1 gene5. Little is known about the molecular basis of these… 

Differential requirements of the fused kinase for hedgehog signalling in the Drosophila embryo.

Hedgehog responsive ventral cells in embryos can be divided into two distinct types depending on their requirement for Fused activity, and the existence of position-specific modulators of the Hedgehog response is proposed.

Spatial regulation of a zebrafish patched homologue reflects the roles of sonic hedgehog and protein kinase A in neural tube and somite patterning.

It is shown that expression of patched1 as well as of other sonic hedgehog targets, is regulated by protein kinase A activity, suggesting that the mechanism of signalling by Hedgehog family proteins has been highly conserved during evolution.

Signal transduction by cAMP-dependent protein kinase A in Drosophila limb patterning

Evidence is presented that removing activity of the gene encoding cyclic AMP-dependent protein kinase A (pka) is functionally equivalent to removing ptc activity or to providing cells with the Hh signal, which is a component of the signal transduction pathway through which Hh and Ptc direct localized expression of dpp and establish the compartment boundary organizer.

Cubitus interruptus-independent transduction of the Hedgehog signal in Drosophila.

It is shown that it is required positively for rhomboid expression and that Teashirt and Ci act in a partially redundant manner before stage 11 to maintain wingless expression in the trunk.

Expression of wingless in the Drosophila embryo: a conserved cis-acting element lacking conserved Ci-binding sites is required for patched-mediated repression.

It is shown that wg regulatory DNA can drive lacZ in a proper wg-like pattern without any conserved Ci-binding sites and suggest that Ci can not be the sole endpoint of the Hh pathway.



Cell patterning in the Drosophila segment: spatial regulation of the segment polarity gene patched.

The contribution of other segment polarity gene functions to the evolution of this pattern is analysed and it is found that the first step in patched regulation is under the control of engrailed whereas the second requires the activity of both cubitus interruptusD and patched itself.

Regulation of segment polarity genes in the Drosophila blastoderm by fushi tarazu and even skipped

It is proposed that the precise positioning of the en stripes depends upon signals generated in a combinatorial manner by the overlaps between the ftz or eve domains and those of other pair rule genes, specifically odd paired, opa and paired, prd11,16,17.

Role of segment polarity genes in the definition and maintenance of cell states in the Drosophila embryo.

It is suggested that positional information is encoded in cell states defined and maintained by the activity of segment polarity gene products.

Molecular cloning of sequences from wingless, a segment polarity gene in Drosophila: the spatial distribution of a transcript in embryos

The cloning of sequences from a segment‐polarity gene, wingless, and the in situ localization of a transcript in embryos are described, which discusses the pattern of expression with respect to models of pattern formation in segmental units.

Requirements for hedgehog, a segmental polarity gene, in patterning larval and adult cuticle of Drosophila.

A type of "domineering" nonautonomy is proposed for the activity of the hedgehog gene because defects in the distal portions of the legs and antenna occur in association with homozygous hedgehog clones in the posterior compartment of those structures.

Region-specific recombination and expression are directed by portions of the Drosophila engrailed promoter.

To investigate how theEngrailed gene is regulated, chimeric genes consisting of fragments of the engrailed promoter and Escherichia coli lacZ were incorporated into the Drosophila germ line by P-element-mediated recombination.