title: FGF signaling regulates rod photoreceptor cell maintenance and regeneration in zebrafish.
abstract: Fgf signaling is required for many biological processes involving the regulation of cell proliferation and maintenance, including embryonic patterning, tissue homeostasis, wound healing, and cancer progression. Although the function of Fgf signaling is suggested in several different regeneration models, including appendage regeneration in amphibians and fin and heart regeneration in zebrafish, it has not yet been studied during zebrafish photoreceptor cell regeneration. Here we demonstrate that intravitreal injections of FGF-2 induced rod precursor cell proliferation and photoreceptor cell neuroprotection during intense light damage. Using the dominant-negative Tg(hsp70:dn-fgfr1) transgenic line, we found that Fgf signaling was required for homeostasis of rod, but not cone, photoreceptors. Even though fgfr1 is expressed in both rod and cone photoreceptors, we found that Fgf signaling differentially affected the regeneration of cone and rod photoreceptors in the light-damaged retina, with the dominant-negative hsp70:dn-fgfr1 transgene significantly repressing rod photoreceptor regeneration without affecting cone photoreceptors. These data suggest that rod photoreceptor homeostasis and regeneration is Fgf-dependent and that rod and cone photoreceptors in adult zebrafish are regulated by different signaling pathways.
authors.affiliation: Department of Molecular, Cellular, and Developmental Biology, University of Michigan College of Literature, Science, and the Arts, 830 North University, Ann Arbor, MI 48109, USA. qinzhao@umich.edu
authors.forename: Zhao
authors.initials: Z
authors.lastname: Qin
authors.forename: Ambrose R
authors.initials: AR
authors.lastname: Kidd
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Thomas
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Poss
authors.forename: David R
authors.initials: DR
authors.lastname: Hyde
authors.forename: Pamela A
authors.initials: PA
authors.lastname: Raymond
authors.forename: Ryan
authors.initials: R
authors.lastname: Thummel
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D017209:Apoptosis; D049109:Cell Proliferation; D019610:Cytoprotection; D005346:Fibroblast Growth Factors / Q000502:physiology*; D019084:Fluorescent Antibody Technique, Indirect; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics; D006706:Homeostasis / Q000502:physiology; D017403:In Situ Hybridization; D020287:In Situ Nick-End Labeling; D008856:Microscopy, Fluorescence; D051496:Receptor, Fibroblast Growth Factor, Type 1 / Q000378:metabolism; D012038:Regeneration / Q000502:physiology*; D017949:Retinal Cone Photoreceptor Cells / Q000473:pathology; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000502:physiology*
chemical_list: D018840:HSP70 Heat-Shock Proteins; D029961:Zebrafish Proteins; D005346:Fibroblast Growth Factors; D051496:Receptor, Fibroblast Growth Factor, Type 1