title: A conserved function of the zinc finger transcription factor Sp8/9 in allometric appendage growth in the milkweed bug Oncopeltus fasciatus.
abstract: The genes encoding the closely related zinc finger transcription factors Buttonhead (Btd) and D-Sp1 are expressed in the developing limb primordia of Drosophila melanogaster and are required for normal growth of the legs. The D-Sp1 homolog of the red flour beetle Tribolium castaneum, Sp8 (appropriately termed Sp8/9), is also required for the proper growth of the leg segments. Here we report on the isolation and functional study of the Sp8/9 gene from the milkweed bug Oncopeltus fasciatus. We show that Sp8/9 is expressed in the developing appendages throughout development and that the downregulation of Sp8/9 via RNAi leads to antennae, rostrum, and legs with shortened and fused segments. This supports a conserved role of Sp8/9 in allometric leg segment growth. However, all leg segments including the claws are present and the expression of the leg genes Distal-less, dachshund, and homothorax are proportionally normal, thus providing no evidence for a role of Sp8/9 in appendage specification.
authors.affiliation: Georg-August-Universität, Johann-Friedrich-Blumenbach-Institut für Zoologie und Anthropologie, Abteilung Entwicklungsbiologie, GZMB, Ernst-Caspari-Haus, Justus-von-Liebig-Weg 11, Göttingen, Germany.
authors.forename: Nina D
authors.initials: ND
authors.lastname: Schaeper
authors.forename: Nikola-Michael
authors.initials: NM
authors.lastname: Prpic
authors.forename: Ernst A
authors.initials: EA
authors.lastname: Wimmer
mesh_terms: D000818:Animals; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000378:metabolism; D005121:Extremities / Q000254:growth & development; D018507:Gene Expression Regulation, Developmental; D020062:Heteroptera / Q000254:growth & development* / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; D014157:Transcription Factors