title: Negative regulation of dorsoventral signaling by the homeotic gene Ultrabithorax during haltere development in Drosophila.
abstract: Growth and patterning during Drosophila wing development are mediated by signaling from its dorsoventral (D/V) organizer. In the metathorax, wing development is essentially suppressed by the homeotic selector gene Ultrabithorax (Ubx) to mediate development of a pair of tiny balancing organs, the halteres. Here we show that expression of Ubx in the haltere D/V boundary down-regulates its D/V organizer signaling compared to that of the wing D/V boundary. Somatic loss of Ubx from the haltere D/V boundary thus results in the formation of a wing-type D/V organizer in the haltere field. Long-distance signaling from this organizer was analyzed by assaying the ability of a Ubx(-) clone induced in the haltere D/V boundary to effect homeotic transformation of capitellum cells away from the boundary. The clonally restored wing D/V organizer in mosaic halteres not only enhanced the homeotic transformation of Ubx(-) cells in the capitellum but also caused homeotic transformation of even Ubx(+) cells in a genetic background known to induce excessive cell proliferation in the imaginal discs. In addition to demonstrating a non-cell-autonomous role for Ubx during haltere development, these results reveal distinct spatial roles of Ubx during maintenance of cell fate and patterning in the halteres.
authors.affiliation: Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, 500 007, India. shashiccmb.ap.nic.in
authors.forename: L S
authors.initials: LS
authors.lastname: Shashidhara
authors.forename: N
authors.initials: N
authors.lastname: Agrawal
authors.forename: R
authors.initials: R
authors.lastname: Bajpai
authors.forename: V
authors.initials: V
authors.lastname: Bharathi
authors.forename: P
authors.initials: P
authors.lastname: Sinha
mesh_terms: D000818:Animals; D004268:DNA-Binding Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004330:Drosophila / Q000196:embryology*; D029721:Drosophila Proteins; D004627:Embryonic Induction; D005801:Genes, Homeobox; D018398:Homeodomain Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008465:Mechanoreceptors / Q000196:embryology*; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000302:isolation & purification; D009687:Nuclear Proteins / Q000302:isolation & purification; D017956:Photoreceptor Cells, Invertebrate / Q000196:embryology; D011518:Proto-Oncogene Proteins / Q000302:isolation & purification; D012679:Sense Organs / Q000196:embryology*; D014018:Tissue Distribution; D014157:Transcription Factors; D014921:Wings, Animal / Q000196:embryology; D051155:Wnt1 Protein
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D014157:Transcription Factors; C066177:Ubx protein, Drosophila; D051155:Wnt1 Protein; C066381:ct protein, Drosophila; C095064:vg protein, Drosophila; C074622:wg protein, Drosophila