title: The double-stranded RNA-binding protein Staufen 2 regulates eye size.
abstract: Regulation of tissue size is a poorly understood process. Mammalian Staufen 2 (Stau2) is a double-stranded mRNA binding protein known to regulate dendrite formation in vitro as well as cell survival and migration in vivo. Three Stau2 isoforms have been identified in the brain of mammals. Here we show that all these Stau2 isoforms are also expressed in the developing eye of chicken embryos. Strikingly, ectopic expression of Stau2 was sufficient to increase eye size, suggesting a novel biological role of Stau2 in eye morphogenesis. Moreover, down regulation of Stau2 in vivo resulted in a small eye. Microphthalmia was not associated with either increased cell death or differentiation but with reduced cell proliferation. Rescue experiments showed that all three Stau2 isoforms present in the developing eye could prevent microphthalmia. Finally, we showed that Stau2 silencing decreased HES-1 and Sox-2 in the developing eye. These data highlight a new biological function for Stau2 and suggest that translation control of specific Stau2-associated transcripts may be a key regulator of tissue size.
authors.affiliation: Toronto Western Research Institute, Genetics and Development Division, MCL-6-415, Toronto M5T 2S8, Ontario, Canada.
authors.forename: Diane M
authors.initials: DM
authors.lastname: Cockburn
authors.forename: Jason
authors.initials: J
authors.lastname: Charish
authors.forename: Nardos G
authors.initials: NG
authors.lastname: Tassew
authors.forename: James
authors.initials: J
authors.lastname: Eubanks
authors.forename: Rod
authors.initials: R
authors.lastname: Bremner
authors.forename: Paolo
authors.initials: P
authors.lastname: Macchi
authors.forename: Philippe P
authors.initials: PP
authors.lastname: Monnier
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D002642:Chick Embryo; D015536:Down-Regulation; D005123:Eye / Q000196:embryology / Q000254:growth & development* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D020868:Gene Silencing; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D008850:Microphthalmos / Q000235:genetics / Q000378:metabolism; D009929:Organ Size; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D055748:SOXB1 Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D018398:Homeodomain Proteins; D020033:Protein Isoforms; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins; D055748:SOXB1 Transcription Factors; C492188:Stau2 protein, rat