scholarly journals Homeotic selector genes control the patterning of seven-up expressing cells in the Drosophila dorsal vessel

2005 ◽  
Vol 122 (9) ◽  
pp. 1023-1033 ◽  
Author(s):  
Kathryn M. Ryan ◽  
Deborah K. Hoshizaki ◽  
Richard M. Cripps
Keyword(s):  
Dorsal Vessel ◽  
Selector Genes ◽  
Homeotic Selector Genes ◽  
Homeotic Selector

Sequence of the Tribolium castaneum Homeotic Complex: The Region Corresponding to the Drosophila melanogaster Antennapedia Complex

Genetics ◽  
2002 ◽  
Vol 160 (3) ◽  
pp. 1067-1074
Author(s):  
Susan J Brown ◽  
John P Fellers ◽  
Teresa D Shippy ◽  
Elizabeth A Richardson ◽  
Mark Maxwell ◽  
...  
Keyword(s):  
Tribolium Castaneum ◽  
Hox Genes ◽  
Transcription Unit ◽  
Sex Combs Reduced ◽  
Sex Combs ◽  
Selector Genes ◽  
Homeotic Selector Genes ◽  
Encoding Genes ◽  
Single Cluster ◽  
Homeotic Selector

Abstract The homeotic selector genes of the red flour beetle, Tribolium castaneum, are located in a single cluster. We have sequenced the region containing the homeotic selector genes required for proper development of the head and anterior thorax, which is the counterpart of the ANTC in Drosophila. This 280-kb interval contains eight homeodomain-encoding genes, including single orthologs of the Drosophila genes labial, proboscipedia, Deformed, Sex combs reduced, fushi tarazu, and Antennapedia, as well as two orthologs of zerknüllt. These genes are all oriented in the same direction, as are the Hox genes of amphioxus, mice, and humans. Although each transcription unit is similar to its Drosophila counterpart in size, the Tribolium genes contain fewer introns (with the exception of the two zerknüllt genes), produce shorter mRNAs, and encode smaller proteins. Unlike the ANTC, this region of the Tribolium HOMC contains no additional genes.

E(z): a polycomb group gene or a trithorax group gene?

Development ◽  
1996 ◽  
Vol 122 (7) ◽  
pp. 2189-2197 ◽  
Author(s):  
D. LaJeunesse ◽  
A. Shearn
Keyword(s):  
Polycomb Group ◽  
Bithorax Complex ◽  
Trithorax Group ◽  
Polycomb Group Genes ◽  
Enhancer Of Zeste ◽  
Selector Genes ◽  
Homeotic Selector Genes ◽  
Polycomb Group Gene ◽  
Anterior Posterior ◽  
Homeotic Selector

The products of the Polycomb group of genes are cooperatively involved in repressing expression of homeotic selector genes outside of their appropriate anterior/posterior boundaries. Loss of maternal and/or zygotic function of Polycomb group genes results in the ectopic expression of both Antennapedia Complex and Bithorax Complex genes. The products of the trithorax group of genes are cooperatively involved in maintaining active expression of homeotic selector genes within their appropriate anterior/posterior boundaries. Loss of maternal and/or zygotic function of trithorax group genes results in reduced expression of both Antennapedia Complex and Bithorax Complex genes. Although Enhancer of zeste has been classified as a member of the Polycomb group, in this paper we show that Enhancer of zeste can also be classified as a member of the trithorax group. The requirement for Enhancer of zeste activity as either a trithorax group or Polycomb group gene depends on the homeotic selector gene locus as well as on spatial and temporal cues.

The Tribolium homeotic gene Abdominal is homologous to abdominal-A of the Drosophila bithorax complex

Development ◽  
1993 ◽  
Vol 117 (1) ◽  
pp. 233-243 ◽  
Author(s):  
J.J. Stuart ◽  
S.J. Brown ◽  
R.W. Beeman ◽  
R.E. Denell
Keyword(s):  
Molecular Analysis ◽  
Tribolium Castaneum ◽  
Functional Significance ◽  
Homeotic Gene ◽  
Bithorax Complex ◽  
Developmental Genetic ◽  
Selector Genes ◽  
Homeotic Selector Genes ◽  
Homeotic Selector

The Abdominal gene is a member of the single homeotic complex of the beetle, Tribolium castaneum. An integrated developmental genetic and molecular analysis shows that Abdominal is homologous to the abdominal-A gene of the bithorax complex of Drosophila. abdominal-A mutant embryos display strong homeotic transformations of the anterior abdomen (parasegments 7–9) to PS6, whereas developmental commitments in the posterior abdomen depend primarily on Abdominal-B. In beetle embryos lacking Abdominal function, parasegments throughout the abdomen are transformed to PS6. This observation demonstrates the general functional significance of parasegmental expression among insects and shows that the control of determinative decisions in the posterior abdomen by homeotic selector genes has undergone considerable evolutionary modification.

scholarly journals extradenticle determines segmental identities throughout Drosophila development

Development ◽  
1995 ◽  
Vol 121 (11) ◽  
pp. 3663-3673 ◽  
Author(s):  
C. Rauskolb ◽  
K.M. Smith ◽  
M. Peifer ◽  
E. Wieschaus
Keyword(s):  
Adult Development ◽  
Target Genes ◽  
Fusion Gene ◽  
Head Capsule ◽  
Downstream Target ◽  
Heat Shocks ◽  
Selector Genes ◽  
Inappropriate Expression ◽  
Homeotic Selector

extradenticle (exd) and the homeotic selector proteins together establish segmental identities by coordinately regulating the expression of downstream target genes. The inappropriate expression of these targets in exd mutant embryos results in homeotic transformations and aberrant morphogenesis. Here we examine the role of exd in adult development by using genetic mosaics and a hypomorphic exd allele caused by a point mutation in the homeodomain. exd continues to be essential for the specification of segmental identities, consistent with a continuing requirement for exd as cofactor of the homeotic selector proteins. Loss of exd results in the homeotic transformation of abdominal segments to an A5 or A6 segmental identity, the antenna and arista to leg, and the head capsule to dorsal thorax or notum. Proximal leg structures are particularly sensitive to the loss of exd, although exd does not affect the allocation of proximal positional values of the leg imaginal disc. Using heat-shocks to induce expression of a hsp70-exd fusion gene, we show that, in contrast to the homeotic selector genes, ubiquitously high levels of exd expression do not cause pattern abnormalities or segmental transformations.

Regulation of proboscipedia in Drosophila by Homeotic Selector Genes

Genetics ◽  
2000 ◽  
Vol 156 (1) ◽  
pp. 183-194
Author(s):  
Douglas B Rusch ◽  
Thomas C Kaufman
Keyword(s):  
Expression Pattern ◽  
Regulatory Element ◽  
Polycomb Group ◽  
Accumulation Pattern ◽  
Cis Acting ◽  
Polycomb Group Genes ◽  
Gap Genes ◽  
Combined Action ◽  
Selector Genes

Abstract The gene proboscipedia (pb) is a member of the Antennapedia complex in Drosophila and is required for the proper specification of the adult mouthparts. In the embryo, pb expression serves no known function despite having an accumulation pattern in the mouthpart anlagen that is conserved across several insect orders. We have identified several of the genes necessary to generate this embryonic pattern of expression. These genes can be roughly split into three categories based on their time of action during development. First, prior to the expression of pb, the gap genes are required to specify the domains where pb may be expressed. Second, the initial expression pattern of pb is controlled by the combined action of the genes Deformed (Dfd), Sex combs reduced (Scr), cap'n'collar (cnc), and teashirt (tsh). Lastly, maintenance of this expression pattern later in development is dependent on the action of a subset of the Polycomb group genes. These interactions are mediated in part through a 500-bp regulatory element in the second intron of pb. We further show that Dfd protein binds in vitro to sequences found in this fragment. This is the first clear demonstration of autonomous positive cross-regulation of one Hox gene by another in Drosophila melanogaster and the binding of Dfd to a cis-acting regulatory element indicates that this control might be direct.

Smoothened-mediated Hedgehog signalling is required for the maintenance of the anterior-posterior lineage restriction in the developing wing of Drosophila

Development ◽  
1997 ◽  
Vol 124 (20) ◽  
pp. 4053-4063 ◽  
Author(s):  
S.S. Blair ◽  
A. Ralston
Keyword(s):  
Gene Expression ◽  
Cellular Mechanisms ◽  
Hedgehog Signalling ◽  
Compartment Boundary ◽  
Complex Process ◽  
Normal Site ◽  
Selector Genes ◽  
Signalling Models ◽  
To Receive ◽  
Anterior Posterior

It is thought that the posterior expression of the ‘selector’ genes engrailed and invected control the subdivision of the growing wing imaginal disc of Drosophila into anterior and posterior lineage compartments. At present, the cellular mechanisms by which separate lineage compartments are maintained are not known. Most models have assumed that the presence or absence of selector gene expression autonomously drives the expression of compartment-specific adhesion or recognition molecules that inhibit intermixing between compartments. However, our present understanding of Hedgehog signalling from posterior to anterior cells raises some interesting alternative models based on a cell's response to signalling. We show here that anterior cells that lack smoothened, and thus the ability to receive the Hedgehog signal, no longer obey a lineage restriction in the normal position of the anterior-posterior boundary. Rather these clones extend into anatomically posterior territory, without any changes in engrailed/invected gene expression. We have also examined clones lacking both en and inv; these too show complex behaviors near the normal site of the compartment boundary, and do not always cross entirely into anatomically anterior territory. Our results suggest that compartmentalization is a complex process involving intercompartmental signalling; models based on changes in affinity or growth will be discussed.

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