scholarly journals Spatial regulation of segment polarity gene expression in the anterior terminal region of the Drosophila blastoderm embryo

1995 ◽  
Vol 50 (2-3) ◽  
pp. 151-161 ◽  
Author(s):  
Jym Mohler
Keyword(s):  
Gene Expression ◽  
Terminal Region ◽  
Spatial Regulation ◽  
Segment Polarity ◽  
Segment Polarity Gene ◽  
Polarity Gene

Control of Drosophila head segment identity by the bZIP homeotic gene cnc

Development ◽  
1995 ◽  
Vol 121 (1) ◽  
pp. 237-247 ◽  
Author(s):  
J. Mohler ◽  
J.W. Mahaffey ◽  
E. Deutsch ◽  
K. Vani
Keyword(s):  
Gene Expression ◽  
Mutational Analysis ◽  
Bzip Transcription Factor ◽  
Homeotic Gene ◽  
Head Region ◽  
Segment Polarity ◽  
Mandibular Segment ◽  
Segment Polarity Gene ◽  
Polarity Gene

Mutational analysis of cap'n'collar (cnc), a bZIP transcription factor closely related to the mammalian erythroid factor NF-E2 (p45), indicates that it acts as a segment-specific selector gene controlling the identity of two cephalic segments. In the mandibular segment, cnc has a classical homeotic effect: mandibular structures are missing in cnc mutant larvae and replaced with duplicate maxillary structures. We propose that cnc functions in combination with the homeotic gene Deformed to specify mandibular development. Labral structures are also missing in cnc mutant larvae, where a distinct labral primordia is not properly maintained in the developing foregut, as observed by the failure to maintain and elaborate patterns of labral-specific segment polarity gene expression. Instead, the labral primordium fuses with the esophageal primordium to contribute to formation of the esophagus. The role of cnc in labral development is reciprocal to the role of homeotic gene forkhead, which has an identical function in the maintenance of the esophageal primordium. This role of homeotic selector genes for the segment-specific maintenance of segment polarity gene expression is a unique feature of segmentation in the preoral head region of Drosophila.

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

Development ◽  
1990 ◽  
Vol 110 (1) ◽  
pp. 291-301 ◽  
Author(s):  
A. Hidalgo ◽  
P. Ingham
Keyword(s):  
Broad Band ◽  
Positional Information ◽  
Drosophila Embryo ◽  
Normal Pattern ◽  
Anterior Portion ◽  
Spatial Regulation ◽  
Segment Polarity Genes ◽  
Segment Polarity ◽  
Segment Polarity Gene ◽  
Polarity Gene

Intrasegmental patterning in the Drosophila embryo requires the activity of the segment polarity genes. The acquisition of positional information by cells during embryogenesis is reflected in the dynamic patterns of expression of several of these genes. In the case of patched, early ubiquitous expression is followed by its repression in the anterior portion of each parasegment; subsequently each broad band of expression splits into two narrow stripes. In this study we analyse the contribution of other segment polarity gene functions to the evolution of this pattern; we find 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. Furthermore, the products of engrailed, wingless and hedgehog are essential for maintaining the normal pattern of expression of patched.

Positional signaling by hedgehog in Drosophila imaginal disc development

Development ◽  
1995 ◽  
Vol 121 (1) ◽  
pp. 1-10 ◽  
Author(s):  
A.L. Felsenfeld ◽  
J.A. Kennison
Keyword(s):  
Hedgehog Signaling ◽  
Imaginal Disc ◽  
Ectopic Expression ◽  
Posterior Compartment ◽  
Anterior Compartment ◽  
Segment Polarity ◽  
Wing Structures ◽  
Wing Discs ◽  
Segment Polarity Gene ◽  
Polarity Gene

We describe a dominant gain-of-function allele of the segment polarity gene hedgehog. This mutation causes ectopic expression of hedgehog mRNA in the anterior compartment of wing discs, leading to overgrowth of tissue in the anterior of the wing and partial duplication of distal wing structures. The posterior compartment of the wing is unaffected. Other imaginal derivatives are affected, resulting in duplications of legs and antennae and malformations of eyes. In mutant imaginal wing discs, expression of the decapentaplegic gene, which is implicated in the hedgehog signaling pathway, is also perturbed. The results suggest that hedgehog protein acts in the wing as a signal to instruct neighboring cells to adopt fates appropriate to the region of the wing just anterior to the compartmental boundary.

rasp, a putative transmembrane acyltransferase, is required for Hedgehog signaling

Development ◽  
2002 ◽  
Vol 129 (4) ◽  
pp. 843-851 ◽  
Author(s):  
Craig A. Micchelli ◽  
Inge The ◽  
Erica Selva ◽  
Vladic Mogila ◽  
Norbert Perrimon
Keyword(s):  
Hedgehog Signaling ◽  
Transmembrane Protein ◽  
Post Translational Modification ◽  
Protein Levels ◽  
Lethal Mutations ◽  
Segment Polarity ◽  
Invertebrate Development ◽  
Membrane Bound ◽  
Segment Polarity Gene ◽  
Polarity Gene

Members of the Hedgehog (Hh) family encode secreted molecules that act as potent organizers during vertebrate and invertebrate development. Post-translational modification regulates both the range and efficacy of Hh protein. One such modification is the acylation of the N-terminal cysteine of Hh. In a screen for zygotic lethal mutations associated with maternal effects, we have identified rasp, a novel Drosophila segment polarity gene. Analysis of the rasp mutant phenotype, in both the embryo and wing imaginal disc demonstrates that rasp does not disrupt Wnt/Wingless signaling but is specifically required for Hh signaling. The requirement of rasp is restricted only to those cells that produce Hh; hh transcription, protein levels and distribution are not affected by the loss of rasp. Molecular analysis reveals that rasp encodes a multipass transmembrane protein that has homology to a family of membrane bound O-acyl transferases. Our results suggest that Rasp-dependent acylation is necessary to generate a fully active Hh protein.

Transcription of the segment-polarity gene wingless in the imaginal discs of Drosophila, and the phenotype of a pupal-lethal wg mutation

Development ◽  
1988 ◽  
Vol 102 (3) ◽  
pp. 489-497 ◽  
Author(s):  
N.E. Baker
Keyword(s):  
In Situ Hybridization ◽  
Imaginal Discs ◽  
Apical Cytoplasm ◽  
Segment Polarity ◽  
Disc Cells ◽  
Segment Polarity Gene ◽  
Drosophila Embryos ◽  
Polarity Gene

Wingless (wg) is a segment-polarity gene in Drosophila which is related to the murine proto-oncogene int1. In Drosophila embryos, wg transcription defines part of each parasegment. In situ hybridization shows that wg is also expressed in the imaginal discs which give rise to the adult during metamorphosis. Transcripts are localized in the apical cytoplasm of disc cells, and accumulate in different patterns in dorsal and ventral discs. The wgCX3 mutation produces morphological defect in the adult structures derived from these imaginal discs. The results show that wg is involved in the development of the adult, as well as the embryo, but that the imaginal discs do not express this segment-polarity gene in an identical pattern to the embryonic segments.

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