title: Numbers and ratios of X-chromosomal-linked opsin genes.
abstract: Quantitative Southern blotting and PCR/RFLP analysis were used to determine the number and ratio of long-wave-sensitive (L-) and mid-wave-sensitive (M-) opsin genes in 25 colour-normal caucasian males. The average observed ratio was 1:2.8 +/- 1.2 for Southern blot analysis and 1:3.0 +/- 1.7 for PCR/RFLP analysis. Thus, the two techniques yielded similar results for the ratio of L- to M-opsin genes (Wilcoxon t-test, P < 0.01). PCR/RFLP analysis of a Sma I polymorphism specific for the most proximal opsin gene suggested an average gene number of 6.0 +/- 2.1, with a range from 4 to 12 in individual subjects. In contrast, Southern blot analysis suggested an average number of 3.8 +/- 1.2, with a range from 2 to 7 (on the assumption that only one L-opsin gene is ever present). Differences between the L- to M-opsin gene ratio and the total gene number in some subjects may result from the presence of multiple L-opsin genes and/or hybrid opsin genes in colour-normal males. An exact determination of the total gene number will require employing other molecular techniques.
authors.affiliation: Universitäts-Augenklinik, Tübingen, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Wolf
authors.forename: L T
authors.initials: LT
authors.lastname: Sharpe
authors.forename: H
authors.initials: H
authors.lastname: Knau
authors.forename: B
authors.initials: B
authors.lastname: Wissinger
mesh_terms: D015139:Blotting, Southern; D004247:DNA / Q000032:analysis; D008040:Genetic Linkage; D006801:Humans; D008297:Male; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D017299:Rod Opsins / Q000235:genetics*; D014960:X Chromosome
chemical_list: D017299:Rod Opsins; D004247:DNA