Abstract
The relationship between the molecular structure of the X-linked red and green visual pigment genes and color-vision phenotype as ascertained by anomaloscopy was studied in 64 color-defective males. The great majority of red-green defects were associated with either the deletion of the green-pigment gene or the formation of 5' red-green hybrid genes or 5' green-red hybrid genes. A rapid PCR-based method allowed detection of hybrid genes, including those undetectable by Southern blot analysis, as well as more precise localization of the fusion points in hybrid genes. Protan color-vision defects appeared always associated with 5' red-green hybrid genes. Carriers of single red-green hybrid genes with fusion in introns 1-4 were protanopes. However, carriers of hybrid genes with red-green fusions in introns 2, 3, or 4 in the presence of additional normal green genes manifested as either protanopes or protanomalous trichromats, with the majority being protanomalous. Deutan defects were associated with green-pigment gene deletions, with 5' green-red hybrid genes, or, rarely, with 5' green-red-green hybrid genes. Complete green-pigment gene deletions or green-red fusions in intron 1 were usually associated with deuteranopia, although we unexpectedly found three carriers of a single red-pigment gene without any green-pigment genes to be deuteranomalous trichromats. All but one of the other deuteranomalous subjects had green-red hybrid genes with intron 1, 2, 3, or 4 fusions, as well as several normal green-pigment genes. The one exception had a grossly normal gene array, presumably with a more subtle mutation. Amino acid differences in exon 5 largely determine whether a hybrid gene will be more redlike or more greenlike in phenotype. Various discrepancies as to severity (dichromacy or trichromacy) remain unexplained but may arise because of variability of expression, postreceptoral variation, or both. When phenotypic color-vision defects exist, the kind of defect (protan or deutan) can be predicted by molecular analysis. Red-green hybrid genes are probably always associated with protan color-vision defects, while the presence of green-red hybrid genes may not always manifest phenotypically with color-vision defects. Four subjects who were found to have 5' green-red hybrid genes in addition to normal red- and green-pigment genes had normal color vision as determined by anomaloscopy. These were discovered among a group of 129 Caucasian males who had been recruited as volunteers for a vision study.(ABSTRACT TRUNCATED AT 400 WORDS)
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- Alpern M., Wake T. Cone pigments in human deutan colour vision defects. J Physiol. 1977 Apr;266(3):595–612. doi: 10.1113/jphysiol.1977.sp011784. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Applebury M. L., Hargrave P. A. Molecular biology of the visual pigments. Vision Res. 1986;26(12):1881–1895. doi: 10.1016/0042-6989(86)90115-x. [DOI] [PubMed] [Google Scholar]
- Breton M. E., Cowan W. B. Deuteranomalous color matching in the deuteranopic eye. J Opt Soc Am. 1981 Oct;11(10):1220–1223. doi: 10.1364/josa.71.001220. [DOI] [PubMed] [Google Scholar]
- Chabre M., Breton J., Michel-Villaz M., Saibil H. Linear dichroism studies in the visible, UV, and IR on oriented rod suspensions. Methods Enzymol. 1982;81:605–616. doi: 10.1016/s0076-6879(82)81084-7. [DOI] [PubMed] [Google Scholar]
- Feil R., Aubourg P., Heilig R., Mandel J. L. A 195-kb cosmid walk encompassing the human Xq28 color vision pigment genes. Genomics. 1990 Feb;6(2):367–373. doi: 10.1016/0888-7543(90)90578-i. [DOI] [PubMed] [Google Scholar]
- Jørgensen A. L., Deeb S. S., Motulsky A. G. Molecular genetics of X chromosome-linked color vision among populations of African and Japanese ancestry: high frequency of a shortened red pigment gene among Afro-Americans. Proc Natl Acad Sci U S A. 1990 Sep;87(17):6512–6516. doi: 10.1073/pnas.87.17.6512. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kosower E. M. Assignment of groups responsible for the "opsin shift" and light absorptions of rhodopsin and red, green, and blue iodopsins (cone pigments). Proc Natl Acad Sci U S A. 1988 Feb;85(4):1076–1080. doi: 10.1073/pnas.85.4.1076. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nagy A. L., Purl K. F. Color discrimination and neural coding in color deficients. Vision Res. 1987;27(3):483–489. doi: 10.1016/0042-6989(87)90096-4. [DOI] [PubMed] [Google Scholar]
- Nathans J. Molecular biology of visual pigments. Annu Rev Neurosci. 1987;10:163–194. doi: 10.1146/annurev.ne.10.030187.001115. [DOI] [PubMed] [Google Scholar]
- Nathans J., Piantanida T. P., Eddy R. L., Shows T. B., Hogness D. S. Molecular genetics of inherited variation in human color vision. Science. 1986 Apr 11;232(4747):203–210. doi: 10.1126/science.3485310. [DOI] [PubMed] [Google Scholar]
- Nathans J., Thomas D., Hogness D. S. Molecular genetics of human color vision: the genes encoding blue, green, and red pigments. Science. 1986 Apr 11;232(4747):193–202. doi: 10.1126/science.2937147. [DOI] [PubMed] [Google Scholar]
- Neitz J., Neitz M., Jacobs G. H. Analysis of fusion gene and encoded photopigment of colour-blind humans. Nature. 1989 Dec 7;342(6250):679–682. doi: 10.1038/342679a0. [DOI] [PubMed] [Google Scholar]
- Orita M., Suzuki Y., Sekiya T., Hayashi K. Rapid and sensitive detection of point mutations and DNA polymorphisms using the polymerase chain reaction. Genomics. 1989 Nov;5(4):874–879. doi: 10.1016/0888-7543(89)90129-8. [DOI] [PubMed] [Google Scholar]
- Saiki R. K., Gelfand D. H., Stoffel S., Scharf S. J., Higuchi R., Horn G. T., Mullis K. B., Erlich H. A. Primer-directed enzymatic amplification of DNA with a thermostable DNA polymerase. Science. 1988 Jan 29;239(4839):487–491. doi: 10.1126/science.2448875. [DOI] [PubMed] [Google Scholar]
- Sanger F., Nicklen S., Coulson A. R. DNA sequencing with chain-terminating inhibitors. Proc Natl Acad Sci U S A. 1977 Dec;74(12):5463–5467. doi: 10.1073/pnas.74.12.5463. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Thomas D. D., Stryer L. Transverse location of the retinal chromophore of rhodopsin in rod outer segment disc membranes. J Mol Biol. 1982 Jan 5;154(1):145–157. doi: 10.1016/0022-2836(82)90422-3. [DOI] [PubMed] [Google Scholar]
- Thuline H. C., Hodgkin W. E., Fraser G. R., Motulsky A. G. Genetics of protan and deutan color-vision anomalies: an instructive family. Am J Hum Genet. 1969 Nov;21(6):581–592. [PMC free article] [PubMed] [Google Scholar]
- Vollrath D., Nathans J., Davis R. W. Tandem array of human visual pigment genes at Xq28. Science. 1988 Jun 17;240(4859):1669–1672. doi: 10.1126/science.2837827. [DOI] [PubMed] [Google Scholar]
- Winderickx J., Lindsey D. T., Sanocki E., Teller D. Y., Motulsky A. G., Deeb S. S. Polymorphism in red photopigment underlies variation in colour matching. Nature. 1992 Apr 2;356(6368):431–433. doi: 10.1038/356431a0. [DOI] [PubMed] [Google Scholar]