scholarly journals The consequences of ubiquitous expression of the wingless gene in the Drosophila embryo

Development ◽  
1992 ◽  
Vol 116 (3) ◽  
pp. 711-719 ◽  
Author(s):  
J. Noordermeer ◽  
P. Johnston ◽  
F. Rijsewijk ◽  
R. Nusse ◽  
P.A. Lawrence
Keyword(s):  
Expression Patterns ◽  
Cell Communication ◽  
Drosophila Embryo ◽  
Cubitus Interruptus ◽  
Segment Polarity ◽  
Type Pattern ◽  
Essential Function ◽  
Segment Polarity Gene ◽  
Local Accumulation ◽  
Made In

The segment polarity gene wingless has an essential function in cell-to-cell communication during various stages of Drosophila development. The wingless gene encodes a secreted protein that affects gene expression in surrounding cells but does not spread far from the cells where it is made. In larvae, wingless is necessary to generate naked cuticle in a restricted part of each segment. To test whether the local accumulation of wingless is essential for its function, we made transgenic flies that express wingless under the control of a hsp70 promoter (HS-wg flies). Uniform wingless expression results in a complete naked cuticle, uniform armadillo accumulation and broadening of the engrailed domain. The expression patterns of patched, cubitus interruptus Dominant and Ultrabithorax follow the change in engrailed. The phenotype of heatshocked HS-wg embryos resembles the segment polarity mutant naked, suggesting that embryos that overexpress wingless or lack the naked gene enter similar developmental pathways. The ubiquitous effects of ectopic wingless expression may indicate that most cells in the embryo can receive and interpret the wingless signal. For the development of the wild-type pattern, it is required that wingless is expressed in a subset of these cells.

Cell patterning in the Drosophila segment: engrailed and wingless antigen distributions in segment polarity mutant embryos

Development ◽  
1993 ◽  
Vol 119 (Supplement) ◽  
pp. 105-114 ◽  
Author(s):  
Marcel van den Heuvel ◽  
John Klingensmith ◽  
Norbert Perrimon ◽  
Roel Nusse
Keyword(s):  
Cell Communication ◽  
Drosophila Embryo ◽  
Current View ◽  
Gene Products ◽  
Cellular Interactions ◽  
Protein Distribution ◽  
Cubitus Interruptus ◽  
Segment Polarity Genes ◽  
Segment Polarity

By a complex and little understood mechanism, segment polarity genes control patterning in each segment of the Drosophila embryo. During this process, cell to cell communication plays a pivotal role and is under direct control of the products of segment polarity genes. Many of the cloned segment polarity genes have been found to be highly conserved in evolution, providing a model system for cellular interactions in other organisms. In Drosophila, two of these genes, engrailed and wingless, are expressed on either side of the parasegment border, wingless encodes a secreted molecule and engrailed a nuclear protein with a homeobox. Maintenance of engrailed expression is dependent on wingless and vice versa. To investigate the role of other segment polarity genes in the mutual control between these two genes, we have examined wingless and engrailed protein distribution in embryos mutant for each of the segment polarity genes. In embryos mutant for armadillo, dishevelled and porcupine, the changes in engrailed expression are identical to those in wingless mutant embryos, suggesting that their gene products act in the wingless pathway. In embryos mutant for hedgehog, fused, cubitus interruptus Dominant and gooseberry, expression of engrailed is affected to varying degrees. However wingless expression in the latter group decays in a similar way earlier than engrailed expression, indicating that these gene products might function in the maintenance of wingless expression. Using double mutant embryos, epistatic relationships between some segment polarity genes have been established. We present a model showing a current view of segment polarity gene interactions.

Molecular organization and embryonic expression of the hedgehog gene involved in cell-cell communication in segmental patterning of Drosophila

Development ◽  
1992 ◽  
Vol 115 (4) ◽  
pp. 957-971 ◽  
Author(s):  
J. Mohler ◽  
K. Vani
Keyword(s):  
Transmembrane Protein ◽  
Cell Communication ◽  
Protein Product ◽  
Drosophila Embryo ◽  
Molecular Organization ◽  
Posterior Portion ◽  
Segment Polarity ◽  
Segment Polarity Gene ◽  
Polarity Gene ◽  
Cell Cell

hedgehog is a segment polarity gene necessary to maintain the proper organization of each segment of the Drosophila embryo. We have identified the physical location of a number of rearrangement breakpoints associated with hedgehog mutations. The corresponding hh RNA is expressed in a series of segmental stripes starting at cellular blastoderm in the posterior portion of each segment. This RNA is localized predominantly within nuclei until stage 10, when the localization becomes primarily cytoplasmic. Expression of hh RNA in the posterior compartment is independent of most other segment polarity genes, including en, until the late extended germ-band stage (stage 11). Sequence analysis of the hedgehog locus suggests the protein product is a transmembrane protein, which may, therefore, be directly involved in cell-cell communication.

scholarly journals Studying the effect of cell division on expression patterns of the segment polarity genes

2008 ◽  
Vol 5 (suppl_1) ◽  
Author(s):  
Madalena Chaves ◽  
Réka Albert
Keyword(s):  
Cell Division ◽  
Expression Patterns ◽  
Gene Expression Pattern ◽  
Specific Gene ◽  
Biological Processes ◽  
Segment Polarity Genes ◽  
Genes Expression ◽  
Its Gene ◽  
Segment Polarity ◽  
Segment Polarity Gene

The segment polarity gene family, and its gene regulatory network, is at the basis of Drosophila embryonic development. The network's capacity for generating and robustly maintaining a specific gene expression pattern has been investigated through mathematical modelling. The models have provided several useful insights by suggesting essential network links, or uncovering the importance of the relative time scales of different biological processes in the formation of the segment polarity genes' expression patterns. But the developmental pattern formation process raises many other questions. Two of these questions are analysed here: the dependence of the signalling protein sloppy paired on the segment polarity genes and the effect of cell division on the segment polarity genes' expression patterns. This study suggests that cell division increases the robustness of the segment polarity network with respect to perturbations in biological processes.

Subcellular localization of the segment polarity protein patched suggests an interaction with the wingless reception complex in Drosophila embryos

Development ◽  
1994 ◽  
Vol 120 (4) ◽  
pp. 987-998 ◽  
Author(s):  
J. Capdevila ◽  
F. Pariente ◽  
J. Sampedro ◽  
J.L. Alonso ◽  
I. Guerrero
Keyword(s):  
Transmembrane Protein ◽  
Cell Communication ◽  
Epidermal Cells ◽  
Communication Processes ◽  
Segment Polarity ◽  
Membrane Bound ◽  
Endocytic Vesicles ◽  
Segment Polarity Gene ◽  
Drosophila Embryos ◽  
Polarity Gene

The product of the segment polarity gene patched is a transmembrane protein involved in the cell communication processes that establish polarity within the embryonic segments of Drosophila. Monoclonal antibodies have been raised against the patched protein, and by immunoelectron microscopy part of the patched staining is found associated with discrete regions of the lateral plasma membrane of the embryonic epidermal cells. Using a mutation affecting endocytosis (shibire) we find that patched is a membrane-bound protein, which is internalized by endocytosis, and that the preferential sites of accumulation resemble the described localization of the cell-cell adhesive junctions of the epidermal cells. patched partially co-localizes with the wingless protein in the wingless-expressing and nearby cells, in structures that seem to be endocytic vesicles. These data suggest the interaction of patched protein with elements of the reception complex of wingless, as a way to control the wingless expression.

scholarly journals Mutations that alter the timing and pattern of cubitus interruptus gene expression in Drosophila melanogaster.

Genetics ◽  
1995 ◽  
Vol 139 (1) ◽  
pp. 229-240 ◽  
Author(s):  
D C Slusarski ◽  
C K Motzny ◽  
R Holmgren
Keyword(s):  
Serine Threonine Kinase ◽  
Cubitus Interruptus ◽  
Threonine Kinase ◽  
Protein Levels ◽  
Segment Polarity ◽  
Subsequent Elimination ◽  
Wing Veins ◽  
Inappropriate Expression ◽  
Segment Polarity Gene ◽  
Polarity Gene

Abstract The cubitus interruptus (ci) gene is a member of the Drosophila segment polarity gene family and encodes a protein with a zinc finger domain homologous to the vertebrate Gli genes and the nematode tra-1 gene. Three classes of existing mutations in the ci locus alter the regulation of ci expression and can be used to examine ci function during development. The first class of ci mutations causes interruptions in wing veins four and five due to inappropriate expression of the ci product in the posterior compartment of imaginal discs. The second class of mutations eliminates ci protein early in embryogenesis and causes the deletion of structures that are derived from the region including and adjacent to the engrailed expressing cells. The third class of mutations eliminates ci protein later in embryogenesis and blocks the formation of the ventral naked cuticle. The loss of ci expression at these two different stages in embryonic development correlates with the subsequent elimination of wingless expression. Adults heterozygous for the unique ciCe mutation have deletions between wing veins three and four. A similar wing defect is present in animals mutant for the segment polarity gene fused that encodes a putative serine/threonine kinase. In ciCe/+ and fused mutants, the deletions between wing veins three and four correlate with increased ci protein levels in the anterior compartment. Thus, proper regulation of both the ci mRNA and protein appears to be critical for normal Drosophila development.

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.

scholarly journals Cloning and characterization of the segment polarity gene cubitus interruptus Dominant of Drosophila.

1990 ◽  
Vol 4 (6) ◽  
pp. 1053-1067 ◽  
Author(s):  
T V Orenic ◽  
D C Slusarski ◽  
K L Kroll ◽  
R A Holmgren
Keyword(s):  
Cubitus Interruptus ◽  
Segment Polarity ◽  
Segment Polarity Gene ◽  
Polarity Gene

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

Development ◽  
1988 ◽  
Vol 103 (1) ◽  
pp. 157-170 ◽  
Author(s):  
A. Martinez Arias ◽  
N.E. Baker ◽  
P.W. Ingham
Keyword(s):  
Positional Information ◽  
Drosophila Embryo ◽  
Gene Products ◽  
Segment Polarity Genes ◽  
Restricted Domains ◽  
Segment Polarity ◽  
Mutant Phenotypes ◽  
Segment Polarity Gene ◽  
Polarity Gene

Segment polarity genes are expressed and required in restricted domains within each metameric unit of the Drosophila embryo. We have used the expression of two segment polarity genes engrailed (en) and wingless (wg) to monitor the effects of segment polarity mutants on the basic metameric pattern. Absence of patched (ptc) or naked (nkd) functions triggers a novel sequence of en and wg patterns. In addition, although wg and en are not expressed on the same cells absence of either one has effects on the expression of the other. These observations, together with an analysis of mutant phenotypes during development, lead us to suggest that positional information is encoded in cell states defined and maintained by the activity of segment polarity gene products.

Genetic analysis of hedgehog signalling in the Drosophila embryo

Development ◽  
1993 ◽  
Vol 119 (Supplement) ◽  
pp. 115-124 ◽  
Author(s):  
A. J. Forbes ◽  
Y. Nakano ◽  
A. M. Taylor ◽  
P. W. Ingham
Keyword(s):  
Genetic Analysis ◽  
Transcriptional Activation ◽  
Secretory Pathway ◽  
Transcription Unit ◽  
Molecular Structures ◽  
Drosophila Embryo ◽  
Cubitus Interruptus ◽  
Cis Acting ◽  
Segment Polarity Genes ◽  
Segment Polarity

The segment polarity genes play a fundamental role in the patterning of cells within individual body segments of the Drosophila embryo. Two of these genes wingless (wg) and hedgehog (hh) encode proteins that enter the secretory pathway and both are thought to act by instructing the fates of cells neighbouring those in which they are expressed. Genetic analysis bas identified the transcriptional activation of wg as one of the targets of hh activity: here we present evidence that transduction of the hh-encoded signal is mediated by the activity of four other segment polarity genes, patched, fused, costal-2 and cubitus interruptus. The results of our genetic epistatsis analysis together with the molecular structures of the products of these genes where known, suggest a pathway of interactions leading from reception of the hh-encoded signal at the cell membrane to transcriptional activation in the cell nucleus. We have also found that transcription of patched is regulated by the same pathway and describe the identification of cis-acting upstream elements of the ptc transcription unit that mediate this regulation.

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