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Kondo T, Nakamori T, Nagai H, Takeshita A, Kusakabe KT, Okada T. A novel spontaneous mutation of BCAR3 results in extrusion cataracts in CF#1 mouse strain. Mamm Genome 2016; 27:451-9. [PMID: 27364350 DOI: 10.1007/s00335-016-9653-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 06/13/2016] [Indexed: 10/21/2022]
Abstract
A substrain of mice originating from the CF#1 strain (an outbred colony) reared at Osaka Prefecture University (CF#1/lr mice) develops cataracts beginning at 4 weeks of age. Affected mice were fully viable and fertile and developed cataracts by 14 weeks of age. Histologically, CF#1/lr mice showed vacuolation of the lens cortex, swollen lens fibers, lens rupture and nuclear extrusion. To elucidate the mode of inheritance, we analyzed heterozygous mutant hybrids generated from CF#1/lr mice and wild-type BALB/c mice. None of the heterozygous mutants were affected, and the ratio of affected to unaffected mice was 1:3 among the offspring of the heterozygous mutants. For the initial genome-wide screening and further mapping, we used affected progeny of CF#1/lr × (CF#1/lr × BALB/c) mice. We concluded that the cataracts in CF#1/lr mice are inherited through an autosomal recessive mutation and that the mutant gene is located on mouse chromosome 3 between D3Mit79 and D3Mit216. In this region, we identified 8 genes associated with ocular disease. All 8 genes were sequenced and a novel point mutation (1 bp insertion of cytosine) in exon 7 of the Bcar3 gene was identified. This mutation produced a premature stop codon and a truncated protein. In conclusion, we have identified the first spontaneous mutation in the Bcar3 gene associated with lens extrusion cataracts. This novel cataract model may provide further knowledge of the molecular biology of cataractogenesis and the function of the BCAR3 protein.
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Affiliation(s)
- Tomohiro Kondo
- Department of Laboratory Animal Science, Graduate School of Life and Environmental Biosciences, Osaka Prefecture University, 1-58 Rinku Ourai kita, Izumisano, Osaka, 598-8531, Japan.
| | - Taketo Nakamori
- Department of Laboratory Animal Science, Graduate School of Life and Environmental Biosciences, Osaka Prefecture University, 1-58 Rinku Ourai kita, Izumisano, Osaka, 598-8531, Japan
| | - Hiroaki Nagai
- Department of Laboratory Animal Science, Graduate School of Life and Environmental Biosciences, Osaka Prefecture University, 1-58 Rinku Ourai kita, Izumisano, Osaka, 598-8531, Japan
| | - Ai Takeshita
- Department of Laboratory Animal Science, Graduate School of Life and Environmental Biosciences, Osaka Prefecture University, 1-58 Rinku Ourai kita, Izumisano, Osaka, 598-8531, Japan
| | - Ken-Takeshi Kusakabe
- Laboratory of Basic Veterinary Science, The United Graduate School of Veterinary Science, Yamaguchi University, Yamaguchi, 753-8515, Japan
| | - Toshiya Okada
- Department of Laboratory Animal Science, Graduate School of Life and Environmental Biosciences, Osaka Prefecture University, 1-58 Rinku Ourai kita, Izumisano, Osaka, 598-8531, Japan
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Kondo T, Ishiga-Hashimoto N, Nagai H, Takeshita A, Mino M, Morioka H, Kusakabe KT, Okada T. Expression of transforming growth factor β and fibroblast growth factor 2 in the lens epithelium of Morioka cataract mice. Congenit Anom (Kyoto) 2014; 54:104-9. [PMID: 24279395 DOI: 10.1111/cga.12042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Accepted: 11/11/2013] [Indexed: 01/10/2023]
Abstract
In the Morioka cataract (MCT) mice, lens opacity appears at 6 to 8 weeks of age, and swollen lens fiber is electron-microscopically observed at 3 weeks after birth. The present study was designed to characterize the expression of transforming growth factor β (TGFβ) and fibroblast growth factor 2 (FGF2) in the lens epithelium of the MCT mice. Immunohistochemical analysis showed that the expression of TGFβ in the lens epithelium of the MCT mice was stronger than that of the wild-type ddY mice at 2 and 4 weeks after birth. The expression of TGFβ receptors (TGFβRI and TGFβRII) and FGF2 in the lens epithelium of the MCT mice was stronger than that of the wild-type ddY mice at 4 weeks and weaker than that of the wild-type ddY mice at 15 weeks after birth. Using real time polymerase chain reaction (PCR), quantitative RT-PCR analysis showed that expression of TGFβ1 and TGFβ2 mRNA in the lens of 2-week-old MCT mice was significantly higher compared to age-matched wild-type ddY mice. These findings indicate that the lens epithelium of MCT mice has increased expression of TGFβ before cataract affection and that changes in the expression of FGF2 as well as TGFβ may contribute to the progression of the cataract in the mice.
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Affiliation(s)
- Tomohiro Kondo
- Department of Integrated Structural Biosciences, Division of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Izumi-Sano, Japan
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Kondo T, Ishiga-Hashimoto N, Nagai H, Takeshita A, Mino M, Morioka H, Kusakabe KT, Okada T. An increase in apoptosis and reduction in αB-crystallin expression levels in the lens underlie the cataractogenesis of Morioka cataract (MCT) mice. Med Mol Morphol 2011; 44:221-7. [PMID: 22179185 DOI: 10.1007/s00795-010-0531-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Accepted: 10/25/2010] [Indexed: 11/30/2022]
Abstract
We examined the morphological changes in fibers, localization of apoptotic cells, and protein expression of αB-crystallin in the lens of Morioka cataract (MCT) mice, a novel cataract model. Using a scanning electron microscope, swollen lens fibers and enlarged spaces between lens fibers were observed in the lens of 3-week-old MCT mice. At 2 weeks of age (before cataract), the single-strand DNA (ssDNA)-positive (indicating apoptosis) cell ratio of the lens epithelium was significantly higher in MCT than in wild-type ddY mice. At 2 and 4 weeks of age, αB-crystallin protein expression of the lens in MCT mice was significantly lower than that in wild-type ddY mice. These findings suggest that increase in apoptosis and reduction in αBcrystallin level are involved in the cataractogenesis of MCT mice.
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Affiliation(s)
- Tomohiro Kondo
- Department of Integrated Structural Biosciences, Division of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Rinku Ourai Kita, Izumi-Sano, Osaka, Japan
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