ZFIN ID: ZDB-PUB-030210-3
Light stimulates a transducin-independent increase of cytoplasmic Ca2+ and suppression of current in cones from the zebrafish mutant nof
Brockerhoff, S.E., Rieke, F., Matthews, H.R., Taylor, M.R., Kennedy, B., Ankoudinova, I., Niemi, G.A., Tucker, C.L., Xiao, M., Cilluffo, M.C., Fain, G.L., and Hurley, J.B.
Date: 2003
Source: The Journal of neuroscience : the official journal of the Society for Neuroscience   23(2): 470-480 (Journal)
Registered Authors: Brockerhoff, Susan, Hurley, James B., Kennedy, Breandan N., Niemi, Gregory, Taylor, Michael
Keywords: genetic analysis of phototransduction, transducin, cone photoreceptor physiology, light adaptation, photoreceptor mutations, G-protein-mediated signal transduction
MeSH Terms:
  • Adaptation, Ocular/genetics
  • Adaptation, Ocular/physiology
  • Amino Acid Sequence
  • Animals
  • Calcium/metabolism*
  • Cyclic GMP/metabolism
  • Cytoplasm/metabolism*
  • GTP-Binding Proteins/metabolism
  • Homozygote
  • In Situ Hybridization
  • Larva
  • Light*
  • Molecular Sequence Data
  • Mutagenesis
  • Organ Specificity
  • Physical Chromosome Mapping
  • Point Mutation
  • RNA, Messenger/biosynthesis
  • Retinal Cone Photoreceptor Cells/cytology
  • Retinal Cone Photoreceptor Cells/metabolism
  • Retinal Cone Photoreceptor Cells/radiation effects*
  • Signal Transduction/physiology
  • Transducin/deficiency
  • Transducin/genetics
  • Transducin/metabolism*
  • Vision, Ocular/genetics
  • Vision, Ocular/physiology
  • Zebrafish
PubMed: 12533607
ABSTRACT
Transducins couple visual pigments to cGMP hydrolysis, the only recognized phototransduction pathway in vertebrate photoreceptors. Here we describe a zebrafish mutant, no optokinetic response f(w21) (nof), with a nonsense mutation in the gene encoding the alpha subunit of cone transducin. Retinal morphology and levels of phototransduction enzymes are normal in nof retinas, but cone transducin is undetectable. Dark current in nof cones is also normal, but it is insensitive to moderate intensity light. The nof cones do respond, however, to bright light. These responses are produced by a light-stimulated, but transducin- independent, release of Ca2+ into the cone cytoplasm. Thus, in addition to stimulating transducin, light also independently induces release of Ca2+ into the photoreceptor cytoplasm.
ADDITIONAL INFORMATION