title: Sp1 modifies leg-to-wing transdetermination in Drosophila.
abstract: During Drosophila development, the transcription factor Sp1 is necessary for proper leg growth and also to repress wing development. Here we test the role of Sp1 during imaginal disc regeneration. Ubiquitous expression of wg induces a regeneration blastema in the dorsal aspect of the leg disc. Within this outgrowth, the wing selector gene vg is activated in some cells, changing their fate to wing identity in a process known as transdetermination. In this report we demonstrate that reducing the gene copy number of Sp1 significantly increases both the frequency and the area of transdetermination in regenerating leg discs. By examining the expression of known Sp1 target genes, we also show that the proximo-distal patterning gene dachshund is downregulated dorsally, leading to a break in its normal ring-shaped expression pattern. We further report that transdetermination, as evidenced by Vg expression, is only observed when there is a broken ring of Dachshund expression. Combined, these studies establish a role for Sp1 in leg-to-wing transdetermination.
authors.affiliation: Department of Biology, University of Washington, Seattle, WA 98195, USA. ingt@uw.edu
authors.forename: Thomas
authors.initials: T
authors.lastname: Ing
authors.forename: Alexander
authors.initials: A
authors.lastname: Tseng
authors.forename: Anne
authors.initials: A
authors.lastname: Sustar
authors.forename: Gerold
authors.initials: G
authors.lastname: Schubiger
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000235:genetics; D002454:Cell Differentiation; D015536:Down-Regulation / Q000235:genetics; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D005121:Extremities / Q000254:growth & development*; D018507:Gene Expression Regulation, Developmental; D007814:Larva / Q000254:growth & development / Q000378:metabolism; D008954:Models, Biological; D016329:Sp1 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D013194:Staining and Labeling; D015854:Up-Regulation / Q000235:genetics; D014921:Wings, Animal / Q000254:growth & development* / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; D016329:Sp1 Transcription Factor; C403210:Sp1 protein, Drosophila