title: Conserved and divergent functions of Drosophila atonal, amphibian, and mammalian Ath5 genes.
abstract: Insect and vertebrate eyes differ in their formation, cellular composition, neural connectivity, and visual function. Despite this diversity, Drosophila atona and its vertebrate Ortholog in the eye, Ath5, each regulate determination of the first retinal neuron class-R8 photo-receptors and retinal ganglion cells (RGCs)-in their respective organisms. We have performed a cross-species functional comparison of these genes. In ato mutant Drosophila, ectopic Xenopus Ath5 (Xath5) rescues photoreceptor cell development comparably with atonaI. In contrast, mouse Ath5 (Math5) induces formation of very few ommatidia, and most of these lack R8 cells. In the developing frog eye, ectopic atonal, like Xath5, promotes the differentiation RGCs. Despite strong conservation of atonaI, Xath5, and Math5 structure and shared function, other factors must contribute to the species specificity of retinal neuron determination. These observations suggest that the atonaI family may occupy a position in a gene hierarchy where differences in gene regulation or function can be correlated with evolutionary diversity of eye development.
authors.affiliation: Institute of Molecular Pathology, 1030 Vienna, Austria.
authors.forename: Yan
authors.initials: Y
authors.lastname: Sun
authors.forename: Shami L
authors.initials: SL
authors.lastname: Kanekar
authors.forename: Monica L
authors.initials: ML
authors.lastname: Vetter
authors.forename: Sharon
authors.initials: S
authors.lastname: Gorski
authors.forename: Yuh-Nung
authors.initials: YN
authors.lastname: Jan
authors.forename: Tom
authors.initials: T
authors.lastname: Glaser
authors.forename: Nadean L
authors.initials: NL
authors.lastname: Brown
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000502:physiology; D004330:Drosophila / Q000235:genetics* / Q000502:physiology / Q000648:ultrastructure; D029721:Drosophila Proteins; D004627:Embryonic Induction / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D006652:Histological Techniques; D007150:Immunohistochemistry; D051379:Mice / Q000235:genetics*; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000502:physiology; D010786:Photoreceptor Cells / Q000502:physiology; D010957:Plasmids / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000235:genetics* / Q000502:physiology; D014162:Transfection; D014981:Xenopus / Q000235:genetics*; D029867:Xenopus Proteins / Q000235:genetics* / Q000502:physiology
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D009419:Nerve Tissue Proteins; D014157:Transcription Factors; D029867:Xenopus Proteins; C107069:ATOH1 protein, Xenopus; C500943:Atoh1 protein, mouse; C117638:Atoh7 protein, mouse; C491279:NEUROD4 protein, Xenopus; C082142:ato protein, Drosophila