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

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.

Genetics ◽  
2002 ◽  
Vol 160 (3) ◽  
pp. 1067-1074
Author(s):  
Susan J Brown ◽  
John P Fellers ◽  
Teresa D Shippy ◽  
Elizabeth A Richardson ◽  
Mark Maxwell ◽  
...  

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.


Development ◽  
1996 ◽  
Vol 122 (7) ◽  
pp. 2189-2197 ◽  
Author(s):  
D. LaJeunesse ◽  
A. Shearn

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.


2005 ◽  
Vol 122 (9) ◽  
pp. 1023-1033 ◽  
Author(s):  
Kathryn M. Ryan ◽  
Deborah K. Hoshizaki ◽  
Richard M. Cripps

Genetics ◽  
2000 ◽  
Vol 155 (2) ◽  
pp. 721-731 ◽  
Author(s):  
Teresa D Shippy ◽  
Jianhua Guo ◽  
Susan J Brown ◽  
Richard W Beeman ◽  
Robin E Denell

Abstract The Tribolium castaneum homeotic gene maxillopedia (mxp) is the ortholog of Drosophila proboscipedia (pb). Here we describe and classify available mxp alleles. Larvae lacking all mxp function die soon after hatching, exhibiting strong transformations of maxillary and labial palps to legs. Hypomorphic mxp alleles produce less severe transformations to leg. RNA interference with maxillopedia double-stranded RNA results in phenocopies of mxp mutant phenotypes ranging from partial to complete transformations. A number of gain-of-function (GOF) mxp alleles have been isolated based on transformations of adult antennae and/or legs toward palps. Finally, we have characterized the mxp expression pattern in wild-type and mutant embryos. In normal embryos, mxp is expressed in the maxillary and labial segments, whereas ectopic expression is observed in some GOF variants. Although mxp and Pb display very similar expression patterns, pb null embryos develop normally. The mxp mutant larval phenotype in Tribolium is consistent with the hypothesis that an ancestral pb-like gene had an embryonic function that was lost in the lineage leading to Drosophila.


Genetics ◽  
1989 ◽  
Vol 121 (3) ◽  
pp. 517-525 ◽  
Author(s):  
A Shearn

Abstract Mutations in the ash-1 and ash-2 genes of Drosophila melanogaster cause a wide variety of homeotic transformations that are similar to the transformations caused by mutations in the trithorax gene. Based on this similar variety of transformations, it was hypothesized that these genes are members of a functionally related set. Three genetic tests were employed here to evaluate that hypothesis. The first test was to examine interactions of ash-1, ash-2 and trithorax mutations with each other. Double and triple heterozygotes of recessive lethal alleles express characteristic homeotic transformations. For example, double heterozygotes of a null allele of ash-1 and a deletion of trithorax have partial transformations of their first and third legs to second legs and of their halteres to wings. The penetrance of these transformations is reduced by a duplication of the bithorax complex. The second test was to examine interactions with a mutation in the female sterile (1) homeotic gene. The penetrance of the homeotic phenotype in progeny from mutant mothers is increased by heterozygosis for alleles of ash-1 or ash-2 as well as for trithorax alleles. The third test was to examine the interaction with a mutation of the Polycomb gene. The extra sex combs phenotype caused by heterozygosis for a deletion of Polycomb is suppressed by heterozygosis for ash-1, ash-2 or trithorax alleles. The fact that mutations in each of the three genes gave rise to similar results in all three tests represents substantial evidence that ash-1, ash-2 and trithorax are members of a functionally related set of genes.


Development ◽  
1992 ◽  
Vol 114 (3) ◽  
pp. 555-563 ◽  
Author(s):  
K. Ueno ◽  
C.C. Hui ◽  
M. Fukuta ◽  
Y. Suzuki

The E loci in Bombyx mori are expected to contain a homeotic gene complex specifying the identities of the larval abdominal segments. However, the molecular structure of this complex remains to be determined. We have started to analyze the structural changes in the E complex mutations. We used three newly isolated Bombyx homeobox genes as probes. These genes are probably homologues of the Ultrabithorax (Ubx), abdominal-A (abd-A) and Abdominal-B (Abd-B) in the Drosophila bithorax complex, because the amino-acid sequences of the homeobox regions in these Bombyx genes are almost identical to those of Drosophila genes. We found that the Bombyx Ubx and abd-A genes are deleted in the EN chromosome, and the Bombyx abd-A gene is deleted in the ECa chromosome. From these results, we conclude that the Bombyx E complex consists of the Ubx, abd-A and possibly Abd-B genes, which may play similar roles to their homologues in the Drosophila bithorax complex.


1987 ◽  
Vol 6 (3) ◽  
pp. 767-777 ◽  
Author(s):  
Michael Regulski ◽  
Nadine McGinnis ◽  
Robin Chadwick ◽  
William McGinnis

Development ◽  
1990 ◽  
Vol 109 (3) ◽  
pp. 553-566 ◽  
Author(s):  
J.R. Bermingham ◽  
A. Martinez-Arias ◽  
M.G. Petitt ◽  
M.P. Scott

The homeotic genes of Drosophila control the differentiation of segments during development. Mutations in these genes cause one or more segments to develop structures normally found elsewhere in the organism. Several studies have shown that the spatial patterns of homeotic gene transcription are highly complex, and that these precise patterns of transcription are critical to normal development. The homeotic gene Antennapedia (Antp), a member of the Antennapedia Complex, is required for the correct differentiation of thoracic segments in both embryos and adults. The patterns of total Antp transcript and protein accumulation have been described in detail, but the contribution of each promoter to the overall pattern in embryos has not been reported. We have examined in detail the spatial distribution of transcripts from each of the Antp promoters in both embryo sections and whole embryos by in situ hybridization using promoter-specific probes. We show that the transcripts from each of the two promoters accumulate in distinct, but overlapping patterns during embryogenesis. The results demonstrate that the two Antp promoters are differentially regulated in embryos and provide a basis for examining the regulation of the two promoters and characterizing more fully the function of Antp during embryogenesis. In addition, we have examined the regulation of each of the Antp promoters by genes of the bithorax complex (BX-C). We show that in BX-C- embryos both promoters are derepressed in the abdomen.


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