title: Critical role for Fat/Hippo and IIS/Akt pathways downstream of Ultrabithorax during haltere specification in Drosophila.
abstract: In Drosophila, differential development of wing and haltere, which differ in cell size, number and morphology, is dependent on the function of Hox gene Ultrabithorax (Ubx). Here we report our studies on Ubx-mediated regulation of the Fat/Hippo and IIS/dAkt pathways, which control cell number and cell size during development. Over-expression of Yki or down regulation of negative components of the Fat/Hippo pathway, such as expanded, caused considerable increase in haltere size, mainly due to increase in cell number. These phenotypes were also associated with the activation of Akt pathways in developing haltere. Although activation of Akt alone did not affect the cell size or the organ size, we observed dramatic increase in haltere size when Akt was activated in the background where expanded is down regulated. This was associated with the increase in both cell size and cell number. The organ appeared flatter than wildtype haltere and the trichome morphology and spacing resembled that of wing suggesting homeotic transformations. Thus, our results suggest a link between cellular growth and pattern formation and the final differentiated state of the organ.
authors: Indian Institute of Science Education and Research, Pune 411008, India; Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.
authors: Savita
authors: S
authors: Singh
authors: Indian Institute of Science Education and Research, Pune 411008, India; Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.
authors: Ernesto
authors: E
authors: Sánchez-Herrero
authors: Indian Institute of Science Education and Research, Pune 411008, India; Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain. Electronic address: ls.shashidhara@iiserpune.ac.in.
authors: L S
authors: LS
authors: Shashidhara
mesh_terms: D000818:Animals; D015815:Cell Adhesion Molecules / Q000235:genetics*; D002454:Cell Differentiation / Q000235:genetics; D015536:Down-Regulation / Q000235:genetics; D004330:Drosophila / Q000196:embryology / Q000235:genetics*; D029721:Drosophila Proteins / Q000235:genetics*; D005801:Genes, Homeobox / Q000235:genetics*; D018398:Homeodomain Proteins / Q000235:genetics; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics*; D009024:Morphogenesis / Q000235:genetics; D009929:Organ Size; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics*; D015398:Signal Transduction / Q000235:genetics*; D014921:Wings, Animal / Q000196:embryology; D000099317:Hippo Kinases
chemical_list: D015815:Cell Adhesion Molecules; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D047908:Intracellular Signaling Peptides and Proteins; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; C472307:ft protein, Drosophila; C499474:hpo protein, Drosophila; D000099317:Hippo Kinases
keywords: Cell size; Expanded; Haltere; Hox genes; Organ size; Wing; Yorkie