title: The Hippo pathway effector Yki downregulates Wg signaling to promote retinal differentiation in the Drosophila eye.
abstract: The evolutionarily conserved Hippo signaling pathway is known to regulate cell proliferation and maintain tissue homeostasis during development. We found that activation of Yorkie (Yki), the effector of the Hippo signaling pathway, causes separable effects on growth and differentiation of the Drosophila eye. We present evidence supporting a role for Yki in suppressing eye fate by downregulation of the core retinal determination genes. Other upstream regulators of the Hippo pathway mediate this effect of Yki on retinal differentiation. Here, we show that, in the developing eye, Yki can prevent retinal differentiation by blocking morphogenetic furrow (MF) progression and R8 specification. The inhibition of MF progression is due to ectopic induction of Wingless (Wg) signaling and Homothorax (Hth), the negative regulators of eye development. Modulating Wg signaling can modify Yki-mediated suppression of eye fate. Furthermore, ectopic Hth induction due to Yki activation in the eye is dependent on Wg. Last, using Cut (Ct), a marker for the antennal fate, we show that suppression of eye fate by hyperactivation of yki does not change the cell fate (from eye to antenna-specific fate). In summary, we provide the genetic mechanism by which yki plays a role in cell fate specification and differentiation - a novel aspect of Yki function that is emerging from multiple model organisms.
authors.affiliation: Department of Biology, University of Dayton, Dayton, OH 45469, USA.
authors.forename: Erika
authors.initials: E
authors.lastname: Wittkorn
authors.affiliation: Department of Biology, University of Dayton, Dayton, OH 45469, USA.
authors.forename: Ankita
authors.initials: A
authors.lastname: Sarkar
authors.affiliation: Department of Biology, University of Dayton, Dayton, OH 45469, USA.
authors.forename: Kristine
authors.initials: K
authors.lastname: Garcia
authors.affiliation: Department of Biology, University of Dayton, Dayton, OH 45469, USA Premedical Program, University of Dayton, Dayton, OH 45469, USA Center for Tissue Regeneration and Engineering at Dayton (TREND), University of Dayton, Dayton, OH 45469, USA asingh1@udayton.edu mkangosingh1@udayton.edu.
authors.forename: Madhuri
authors.initials: M
authors.lastname: Kango-Singh
authors.affiliation: Department of Biology, University of Dayton, Dayton, OH 45469, USA Premedical Program, University of Dayton, Dayton, OH 45469, USA Center for Tissue Regeneration and Engineering at Dayton (TREND), University of Dayton, Dayton, OH 45469, USA asingh1@udayton.edu mkangosingh1@udayton.edu.
authors.forename: Amit
authors.initials: A
authors.lastname: Singh
mesh_terms: D000818:Animals; D057506:Arthropod Antennae / Q000378:metabolism; D002454:Cell Differentiation; D019070:Cell Lineage; D002470:Cell Survival; D015536:Down-Regulation; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D008954:Models, Biological; D009024:Morphogenesis; D009687:Nuclear Proteins / Q000378:metabolism*; D012160:Retina / Q000166:cytology* / Q000254:growth & development / Q000378:metabolism; D015398:Signal Transduction; D015534:Trans-Activators / Q000378:metabolism*; D051155:Wnt1 Protein / Q000378:metabolism*; D000091102:YAP-Signaling Proteins
chemical_list: D029721:Drosophila Proteins; D009687:Nuclear Proteins; D015534:Trans-Activators; D051155:Wnt1 Protein; D000091102:YAP-Signaling Proteins; C503814:Yki protein, Drosophila; C074622:wg protein, Drosophila
keywords: Drosophila eye; Growth regulation; Hippo signaling; Patterning; Retinal differentiation; Wingless