Ultrabithorax regulates genes at several levels of the wing-patterning hierarchy to shape the development of the Drosophila haltere.
Arthropods and vertebrates are constructed of many serially homologous structures whose individual patterns are regulated by Hox genes. The Hox-regulated target genes and developmental pathways that determine the morphological differences between any homologous structures are not known. The differentiation of the Drosophila haltere from the wing through the action of the Ultrabithorax (Ubx) gene is a classic example of Hox regulation of serial homology, although no Ubx-regulated genes in the haltere have been identified previously. Here, we show that Ubx represses the expression of the Wingless (Wg) signaling protein and a subset of Wg- and Decapentaplegic-activated genes such as spalt-related, vestigial, Serum Response Factor, and achaete-scute, whose products regulate morphological features that differ between the wing and haltere. In addition, we found that some genes in the same developmental pathway are independently regulated by Ubx. Our results suggest that Ubx, and Hox genes in general, independently and selectively regulate genes that act at many levels of regulatory hierarchies to shape the differential development of serially homologous structures.
Weatherbee
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SD
Howard Hughes Medical Institute and Laboratory of Molecular Biology, University of Wisconsin, Madison, Wisconsin 53706, USA. sbcarrol@facstaff.wisc.edu
Halder
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G
Kim
J
J
Hudson
A
A
Carroll
S
S
D000818:Animals; D004268:DNA-Binding Proteins / Q000502:physiology*; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics* / Q000254:growth & development; D018507:Gene Expression Regulation, Developmental; D005801:Genes, Homeobox; D018398:Homeodomain Proteins / Q000502:physiology*; D019476:Insect Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D009024:Morphogenesis; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis* / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000502:physiology; D012097:Repressor Proteins / Q000502:physiology*; D014157:Transcription Factors; D014921:Wings, Animal / Q000254:growth & development*; D051155:Wnt1 Protein
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D019476:Insect Proteins; D011518:Proto-Oncogene Proteins; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; C066177:Ubx protein, Drosophila; D051155:Wnt1 Protein; C064196:dpp protein, Drosophila; C074622:wg protein, Drosophila