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Choy S, Thakur S, Polyakov E, Abdelaziz J, Lloyd E, Enriquez M, Jayan N, Fily Y, McGaugh S, Keene AC, Kowalko JE. Mutations in the albinism gene oca2 alter vision-dependent prey capture behavior in the Mexican tetra. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.17.599419. [PMID: 38948816 PMCID: PMC11212897 DOI: 10.1101/2024.06.17.599419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Understanding the phenotypic consequences of naturally occurring genetic changes, as well as their impact on fitness, is fundamental to understanding how organisms adapt to an environment. This is critical when genetic variants have pleiotropic effects, as determining how each phenotype impacted by a gene contributes to fitness is essential to understand how and why traits have evolved. A striking example of a pleiotropic gene contributing to trait evolution is the oca2 gene, coding mutations in which underlie albinism and reductions of sleep in the blind Mexican cavefish, Astyanax mexicanus. Here, we characterize the effects of mutations in the oca2 gene on larval prey capture. We find that when conspecific surface fish with engineered mutations in the oca2 allele are hunting, they use cave-like, wide angle strikes to capture prey. However, unlike cavefish or surface fish in the dark, which rely on lateral line mediated hunting, oca2 mutant surface fish use vision when striking at prey from wide angles. Finally, we find that while oca2 mutant surface fish do not outcompete pigmented surface siblings in the dark, pigmented fish outcompete albino fish in the light. This raises the possibility that albinism is detrimental to larval feeding in a surface-like lighted environment, but does not have negative consequences for fish in cave-like, dark environments. Together, these results demonstrate that oca2 plays a role in larval feeding behavior in A. mexicanus. Further, they expand our understanding of the pleiotropic phenotypic consequences of oca2 in cavefish evolution.
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Affiliation(s)
- Stefan Choy
- Department of Biological Sciences, Lehigh University, Bethlehem, PA
| | - Sunishka Thakur
- Department of Integrative Biology, University of Texas at Austin, Austin, TX
| | - Ellen Polyakov
- Wilkes Honors College, Florida Atlantic University, Jupiter, FL
| | - Jennah Abdelaziz
- Department of Biological Sciences, Lehigh University, Bethlehem, PA
| | | | - Maya Enriquez
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, MN
| | - Nikita Jayan
- Wilkes Honors College, Florida Atlantic University, Jupiter, FL
| | - Yaouen Fily
- Wilkes Honors College, Florida Atlantic University, Jupiter, FL
| | - Suzanne McGaugh
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, MN
| | - Alex C Keene
- Department of Biology, Texas A&M, College Station, TX
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Chou TH, Hao Z, Alba D, Lazo A, Gallo Afflitto G, Eastwood JD, Porciatti V, Guy J, Yu H. Mitochondrially Targeted Gene Therapy Rescues Visual Loss in a Mouse Model of Leber's Hereditary Optic Neuropathy. Int J Mol Sci 2023; 24:17068. [PMID: 38069388 PMCID: PMC10707051 DOI: 10.3390/ijms242317068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 11/26/2023] [Accepted: 11/29/2023] [Indexed: 12/18/2023] Open
Abstract
Leber's hereditary optic neuropathy (LHON) is a common mitochondrial genetic disease, causing irreversible blindness in young individuals. Current treatments are inadequate, and there is no definitive cure. This study evaluates the effectiveness of delivering wildtype human NADH ubiquinone oxidoreductase subunit 4 (hND4) gene using mito-targeted AAV(MTSAAV) to rescue LHOH mice. We observed a declining pattern in electroretinograms amplitudes as mice aged across all groups (p < 0.001), with significant differences among groups (p = 0.023; Control vs. LHON, p = 0.008; Control vs. Rescue, p = 0.228). Inner retinal thickness and intraocular pressure did not change significantly with age or groups. Compared to LHON mice, those rescued with wildtype hND4 exhibited improved retinal visual acuity (0.29 ± 0.1 cy/deg vs. 0.15 ± 0.1 cy/deg) and increased functional hyperemia response (effect of flicker, p < 0.001, effect of Group, p = 0.004; Interaction Flicker × Group, p < 0.001). Postmortem analysis shows a marked reduction in retinal ganglion cell density in the LHON group compared to the other groups (Effect of Group, p < 0.001, Control vs. LHON, p < 0.001, Control vs. Rescue, p = 0.106). These results suggest that MTSAAV-delivered wildtype hND4 gene rescues, at least in part, visual impairment in an LHON mouse model and has the therapeutic potential to treat this disease.
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Affiliation(s)
| | | | | | | | | | | | - Vittorio Porciatti
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (T.-H.C.); (Z.H.); (D.A.); (A.L.); (G.G.A.); (J.D.E.); (J.G.)
| | | | - Hong Yu
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA; (T.-H.C.); (Z.H.); (D.A.); (A.L.); (G.G.A.); (J.D.E.); (J.G.)
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Arcuri J, Elbaz A, Sharif NA, Bhattacharya SK. Ocular Treatments Targeting Separate Prostaglandin Receptors in Mice Exhibit Alterations in Intraocular Pressure and Optic Nerve Lipidome. J Ocul Pharmacol Ther 2023; 39:541-550. [PMID: 37267222 PMCID: PMC10616952 DOI: 10.1089/jop.2023.0006] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 02/27/2023] [Indexed: 06/04/2023] Open
Abstract
Background: Prostaglandin (PG) receptor agonists are the first-line eyedrop medication treatment for glaucoma. The pathophysiology of this disease is not completely known, and elevated intraocular pressure (IOP) is the key risk factor. The membranes of the axons (of the retinal ganglion cells) passing through the optic nerve (ON) head experience significant damage. Lipids are an essential component of the cell's membranes, and their profile changes owing to neurodegeneration. In this investigation, three agonists for distinct PG receptors were used to lower IOP and to determine their effect on the ON lipids. We utilized DBA/2J mice as a model of progressive IOP increase and C57BL/6J mice as a model of ON crush. Methods: DBA/2J and C57BL/6J mice were treated daily for 2 weeks with Latanoprost, PF-04217329, or Rivenprost. The IOP was measured every 2 days and pattern electroretinogram was conducted for DBA/2J throughout the study. Lipidomics of ONs were performed for each model and treatment group. Results: Of the tested compounds, Latanoprost and Rivenprost were the most effective agents decreasing IOP in DBA/2J mice. Triglyceride levels increased in the ONs of DBA/2J mouse model, but phosphatidylethanolamine levels underwent highest level changes in the C57BL/6J mouse model when treated with Latanoprost. Conclusions: Topical ocular FP- and EP4-receptor agonists appreciably lowered IOP in the DBA/2J mice representing pigmentary glaucoma. The observed changes in ON lipidomics in the different models of neurodegeneration suggest possible use of such measures in the development of more effective medicines for both IOP reduction and ON protection.
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Affiliation(s)
- Jennifer Arcuri
- Department of Ophthalmology, Bascom Palmer Eye Institute, Miller School of Medicine at University of Miami, Miami, Florida, USA
- Miami Integrative Metabolomics Research Center, Miami, Florida, USA
- Molecular Cellular Pharmacology Graduate Program, University of Miami, Miami, Florida, USA
| | - Abdelrahman Elbaz
- Department of Ophthalmology, Bascom Palmer Eye Institute, Miller School of Medicine at University of Miami, Miami, Florida, USA
- Miami Integrative Metabolomics Research Center, Miami, Florida, USA
| | - Najam A. Sharif
- Eye-APC Duke-National University of Singapore Medical School, Singapore
- Singapore Eye Research Institute, Singapore
- Department of Pharmacology and Neuroscience, University of North Texas Health Sciences Center, Fort Worth, Texas, USA
- Department of Pharmacy Sciences, Creighton University, Omaha, Nebraska, USA
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Texas Southern University, Houston, Texas, USA
- Imperial College of Science and Technology, St. Mary's Campus, London, United Kingdom
- Institute of Ophthalmology, University College London, London, United Kingdom
- Ophthalmology Innovation Center and Product Development Division, Santen Inc., Emeryville, California, USA
| | - Sanjoy K. Bhattacharya
- Department of Ophthalmology, Bascom Palmer Eye Institute, Miller School of Medicine at University of Miami, Miami, Florida, USA
- Miami Integrative Metabolomics Research Center, Miami, Florida, USA
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