title: Zebrafish Lbh-like Is Required for Otx2-mediated Photoreceptor Differentiation.
abstract: The homeobox transcription factor orthodenticle homolog 2 (otx2) is supposed as an organizer that orchestrates a transcription factor network during photoreceptor development. However, its regulation in the process remains unclear. In this study, we have identified a zebrafish limb bud and heart-like gene (lbh-like), which is expressed initially at 30 hours post fertilization (hpf) in the developing brain and eyes. Lbh-like knockdown by morpholinos specifically inhibits expression of multiple photoreceptor-specific genes, such as opsins, gnat1, gnat2 and irbp. Interestingly, otx2 expression in the morphants is not significantly reduced until 32 hpf when lbh-like begins to express, but its expression level in 72 hpf morphants is higher than that in wild type embryos. Co-injection of otx2 and its downstream target neuroD mRNAs can rescue the faults in eyes of Lbh-like morphants. Combined with the results of promoter-reporter assay, we suggest that lbh-like is a new regulator of photoreceptor differentiation directly through affecting otx2 expression in zebrafish. Furthermore, knockdown of lbh-like increases the activity of Notch pathway and perturbs the balance among proliferation, differentiation and survival of photoreceptor precursors.
authors.affiliation: 1. State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, ; 2. Graduate University of the Chinese Academy of Sciences, Wuhan 430072, China.
authors.forename: Wen-Hua
authors.initials: WH
authors.lastname: Li
authors.affiliation: 1. State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences.
authors.forename: Li
authors.initials: L
authors.lastname: Zhou
authors.affiliation: 1. State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Li
authors.affiliation: 1. State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences.
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: 1. State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences.
authors.forename: Jian-Tao
authors.initials: JT
authors.lastname: Shi
authors.affiliation: 1. State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, ; 2. Graduate University of the Chinese Academy of Sciences, Wuhan 430072, China.
authors.forename: Yan-Jing
authors.initials: YJ
authors.lastname: Yang
authors.affiliation: 1. State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences.
authors.forename: Jian-Fang
authors.initials: JF
authors.lastname: Gui
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis; D002454:Cell Differentiation / Q000235:genetics*; D049109:Cell Proliferation; D005123:Eye / Q000033:anatomy & histology / Q000196:embryology; D055785:Gene Knockdown Techniques; D005819:Genetic Markers; D008969:Molecular Sequence Data; D051857:Otx Transcription Factors / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D020419:Photoreceptor Cells, Vertebrate / Q000166:cytology*; D016415:Sequence Alignment; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D015027:Zebrafish / Q000235:genetics / Q000254:growth & development*; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
chemical_list: D005819:Genetic Markers; D051857:Otx Transcription Factors; D015534:Trans-Activators; D029961:Zebrafish Proteins; C000606650:lbhl protein, zebrafish; C497662:otx2b protein, zebrafish
keywords: Lbh-like; Notch; otx2; photoreceptor differentiation; retina development