Quantitative genetic analysis of retinal degeneration in the blind cavefish Astyanax mexicanus.

The retina is the light-sensitive tissue of the eye that facilitates vision. Mutations within genes affecting eye development and retinal function cause a host of degenerative visual diseases, including retinitis pigmentosa and anophthalmia/microphthalmia. The characin fish Astyanax mexicanus includ...

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Main Authors: Kelly E O'Quin, Masato Yoshizawa, Pooja Doshi, William R Jeffery
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2013-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC3577753?pdf=render
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author Kelly E O'Quin
Masato Yoshizawa
Pooja Doshi
William R Jeffery
author_facet Kelly E O'Quin
Masato Yoshizawa
Pooja Doshi
William R Jeffery
author_sort Kelly E O'Quin
collection DOAJ
description The retina is the light-sensitive tissue of the eye that facilitates vision. Mutations within genes affecting eye development and retinal function cause a host of degenerative visual diseases, including retinitis pigmentosa and anophthalmia/microphthalmia. The characin fish Astyanax mexicanus includes both eyed (surface fish) and eyeless (cavefish) morphs that initially develop eyes with normal retina; however, early in development, the eyes of cavefish degenerate. Since both surface and cave morphs are members of the same species, they serve as excellent evolutionary mutant models with which to identify genes causing retinal degeneration. In this study, we crossed the eyed and eyeless forms of A. mexicanus and quantified the thickness of individual retinal layers among 115 F(2) hybrid progeny. We used next generation sequencing (RAD-seq) and microsatellite mapping to construct a dense genetic map of the Astyanax genome, scan for quantitative trait loci (QTL) affecting retinal thickness, and identify candidate genes within these QTL regions. The map we constructed for Astyanax includes nearly 700 markers assembled into 25 linkage groups. Based on our scans with this map, we identified four QTL, one each associated with the thickness of the ganglion, inner nuclear, outer plexiform, and outer nuclear layers of the retina. For all but one QTL, cavefish alleles resulted in a clear reduction in the thickness of the affected layer. Comparative mapping of genetic markers within each QTL revealed that each QTL corresponds to an approximately 35 Mb region of the zebrafish genome. Within each region, we identified several candidate genes associated with the function of each affected retinal layer. Our study is the first to examine Astyanax retinal degeneration in the context of QTL mapping. The regions we identify serve as a starting point for future studies on the genetics of retinal degeneration and eye disease using the evolutionary mutant model Astyanax.
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spelling doaj.art-5818bb866a4a40e9a05c595021ed80142022-12-21T18:58:00ZengPublic Library of Science (PLoS)PLoS ONE1932-62032013-01-0182e5728110.1371/journal.pone.0057281Quantitative genetic analysis of retinal degeneration in the blind cavefish Astyanax mexicanus.Kelly E O'QuinMasato YoshizawaPooja DoshiWilliam R JefferyThe retina is the light-sensitive tissue of the eye that facilitates vision. Mutations within genes affecting eye development and retinal function cause a host of degenerative visual diseases, including retinitis pigmentosa and anophthalmia/microphthalmia. The characin fish Astyanax mexicanus includes both eyed (surface fish) and eyeless (cavefish) morphs that initially develop eyes with normal retina; however, early in development, the eyes of cavefish degenerate. Since both surface and cave morphs are members of the same species, they serve as excellent evolutionary mutant models with which to identify genes causing retinal degeneration. In this study, we crossed the eyed and eyeless forms of A. mexicanus and quantified the thickness of individual retinal layers among 115 F(2) hybrid progeny. We used next generation sequencing (RAD-seq) and microsatellite mapping to construct a dense genetic map of the Astyanax genome, scan for quantitative trait loci (QTL) affecting retinal thickness, and identify candidate genes within these QTL regions. The map we constructed for Astyanax includes nearly 700 markers assembled into 25 linkage groups. Based on our scans with this map, we identified four QTL, one each associated with the thickness of the ganglion, inner nuclear, outer plexiform, and outer nuclear layers of the retina. For all but one QTL, cavefish alleles resulted in a clear reduction in the thickness of the affected layer. Comparative mapping of genetic markers within each QTL revealed that each QTL corresponds to an approximately 35 Mb region of the zebrafish genome. Within each region, we identified several candidate genes associated with the function of each affected retinal layer. Our study is the first to examine Astyanax retinal degeneration in the context of QTL mapping. The regions we identify serve as a starting point for future studies on the genetics of retinal degeneration and eye disease using the evolutionary mutant model Astyanax.http://europepmc.org/articles/PMC3577753?pdf=render
spellingShingle Kelly E O'Quin
Masato Yoshizawa
Pooja Doshi
William R Jeffery
Quantitative genetic analysis of retinal degeneration in the blind cavefish Astyanax mexicanus.
PLoS ONE
title Quantitative genetic analysis of retinal degeneration in the blind cavefish Astyanax mexicanus.
title_full Quantitative genetic analysis of retinal degeneration in the blind cavefish Astyanax mexicanus.
title_fullStr Quantitative genetic analysis of retinal degeneration in the blind cavefish Astyanax mexicanus.
title_full_unstemmed Quantitative genetic analysis of retinal degeneration in the blind cavefish Astyanax mexicanus.
title_short Quantitative genetic analysis of retinal degeneration in the blind cavefish Astyanax mexicanus.
title_sort quantitative genetic analysis of retinal degeneration in the blind cavefish astyanax mexicanus
url http://europepmc.org/articles/PMC3577753?pdf=render
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AT williamrjeffery quantitativegeneticanalysisofretinaldegenerationintheblindcavefishastyanaxmexicanus