title: The nucleolar protein Viriato/Nol12 is required for the growth and differentiation progression activities of the Dpp pathway during Drosophila eye development.
abstract: Drosophila Decapentaplegic (Dpp), a member of the BMP2/4 class of the TGF-βs, is required for organ growth, patterning and differentiation. However, much remains to be understood about the mechanisms acting downstream of these multiple roles. Here we investigate this issue during the development of the Drosophila eye. We have previously identified viriato (vito) as a dMyc-target gene encoding a nucleolar protein that is required for proper tissue growth in the developing eye. By carrying out a targeted in vivo double-RNAi screen to identify genes and pathways functioning with Vito during eye development, we found a strong genetic interaction between vito and members of the Dpp signaling pathway including the TGF-β receptors tkv (type I), put (type II), and the co-Smad medea (med). Analyzing the expression of the Dpp receptor Tkv and the activation pattern of the pathway's transducer, p-Mad, we found that vito is required for a correct signal transduction in Dpp-receiving cells. Overall, we validate the use of double RNAi to find specific genetic interactions and, in particular, we uncover a link between the Dpp pathway and Vito, a nucleolar component. vito would act genetically downstream of Dpp, playing an important role in maintaining a sufficient level of Dpp activity for the promotion of eye disc growth and regulation of photoreceptor differentiation in eye development.
authors: Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto 4150-180, Portugal.
authors: Joana
authors: J
authors: Marinho
authors: Torcato
authors: T
authors: Martins
authors: Marta
authors: M
authors: Neto
authors: Fernando
authors: F
authors: Casares
authors: Paulo S
authors: PS
authors: Pereira
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000235:genetics; D019521:Body Patterning / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics / Q000254:growth & development*; D005123:Eye / Q000166:cytology* / Q000254:growth & development*; D005260:Female; D055785:Gene Knockdown Techniques; D017344:Genes, Insect; D008297:Male; D009687:Nuclear Proteins / Q000378:metabolism*; D034622:RNA Interference; D015398:Signal Transduction / Q000235:genetics
chemical_list: D029721:Drosophila Proteins; D009687:Nuclear Proteins; C064196:dpp protein, Drosophila; C581596:vito protein, Drosophila