Publication Date:
2015-08-30
Description:
In 524 Japanese individuals with deutan colour vision defect, 76 had a normal-order pigment gene array, where the L gene is at the first position and the M gene(s) is located downstream. Of these 76 individuals, 69 had a –71A〉C substitution in the M gene without any other mutation. Because the expression of L/M genes is up-regulated by thyroid hormone (T 3 ) in human retinoblastoma WERI cells, we examined the effects of T 3 on promoter activity; T 3 increased the activity of the –71A promoter 2-fold, but it had no effect on the –71C promoter. Similarly, the –71C promoter was much less activated by T 3 than the –71A promoter in HEK293 cells expressing thyroid hormone receptor isoform β2. Such a weak response of the –71C promoter to T 3 may cause a decrease in the number of M cones and/or the density of M pigment during the differentiation of M cones. The average Rayleigh match midpoint was 18.9 ± 4.1 in 162 ordinary deuteranomaly individuals, but was 37.3 ± 9.1 in 63 deuteranomaly individuals with –71C. The –71A〉C substitution was found to be specific to eastern Asia. These results suggest that there may be a new subset of deuteranomaly associated with –71C in the Japanese (and probably eastern Asian) population(s).
Print ISSN:
0021-924X
Electronic ISSN:
1756-2651
Topics:
Biology
,
Chemistry and Pharmacology
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