title: Photoreceptor differentiation during retinal development, growth, and regeneration in a metamorphic vertebrate.
abstract: To test the hypothesis that growth and regeneration of the adult retina involves a mechanistic recapitulation of retinal development, the patterns of photoreceptor differentiation were investigated in the developing retina, as well as growing and regenerating adult retina, of a metamorphic vertebrate, the winter flounder. Only one opsin, of type RH2 (a "green" cone opsin), was expressed in premetamorphic (developing) retina, and a corresponding middle-wavelength visual pigment was observed. In premetamorphic retinas there was no evidence for any other cone opsins or pigments, rods, rod opsin expression, or rod visual pigment. In contrast, a rod opsin (RH1) and three cone opsins (SWS2, RH2, and LWS) were expressed in postmetamorphic (adult) retina, and these opsins were consistent with the observed repertoire of visual pigments. During postmetamorphic retinal growth and regeneration, cones were always produced before rods, but the different cone types were apparently produced simultaneously, suggesting that cone differentiation mechanisms might change after metamorphosis. The results support the hypothesis that photoreceptor differentiation during growth and regeneration of the adult retina involves a recapitulation of mechanisms that control the sequence of photoreceptor production during retinal development.
authors.affiliation: Department of Neuroscience and Physiology, and the Program in Neuroscience, State University of New York, Upstate Medical University, Syracuse, New York 13210, USA.
authors.forename: Michelle M
authors.initials: MM
authors.lastname: Mader
authors.forename: David A
authors.initials: DA
authors.lastname: Cameron
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology; D005432:Flounder; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008675:Metamorphosis, Biological / Q000502:physiology*; D015591:Microspectrophotometry; D008969:Molecular Sequence Data; D020419:Photoreceptor Cells, Vertebrate / Q000166:cytology* / Q000378:metabolism; D012038:Regeneration / Q000502:physiology; D012160:Retina / Q000166:cytology / Q000254:growth & development / Q000502:physiology*; D017949:Retinal Cone Photoreceptor Cells / Q000166:cytology; D017948:Retinal Rod Photoreceptor Cells / Q000166:cytology; D017299:Rod Opsins / Q000096:biosynthesis; D015398:Signal Transduction / Q000502:physiology; D013963:Thyroid Hormones / Q000502:physiology; D013997:Time Factors
chemical_list: D017299:Rod Opsins; D013963:Thyroid Hormones