The molecular basis of dichromatic color vision in males with multiple red and green visual pigment genes
The molecular basis of dichromatic color vision in males with multiple red and green visual pigment genes
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DOI：
10.1093/hmg/11.1.23
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发表时间：
2002-01-01
影响因子：
3.5
通讯作者：
Deeb, SS
中科院分区：
文献类型：
--
作者：
Jagla, WM;Jägle, H;Deeb, SS
我们研究了50名具有x连锁光色素基因阵列中多个基因的中欧血统的红绿色觉缺陷男性（27个后色种和23个前色种）的基因型变异。我们之前已经表明，只有该阵列的前两个基因被表达，并有助于色觉表型。因此，假设是多基因二色视者拥有的前两个基因编码具有相同或几乎相同光谱敏感性的色素：一个基因正常（R或G），另一个基因杂交（G/R或R/G）。编码色素的光谱灵敏度是从发表的体外和体内数据推断出来的。色觉表型通过标准异常镜检查评估。大多数基因型（92%）包含杂交基因，其序列、位置和编码色素与表型完全相关。然而，其中一种或两种原色体的基因序列与原色盲一致，而不是与原色盲一致，因为两种光谱上不同的色素可能由它们的序列编码。其中两种二色人种只有R-和G-光色素基因，没有任何可检测到的G/R-杂交基因，也没有任何迄今已鉴定的点突变或编码/启动子序列缺失。此外，出乎意料的高数量的多基因氘人（11%）在他们最上游的g色素基因中有C203R突变，这表明这种突变的创始效应来自中欧。大约一半的蛋白具有上游的R/ g杂交基因，其外显子2编码序列与下游的g色素基因(s)不同，这与已发表的数据不一致，该数据表明外显子2的单个氨基酸替换可以通过改变视锥细胞的光密度来赋予多基因蛋白红绿辨别能力。
We investigated the genotypic variation in 50 red-green color vision deficient males (27 deuteranopes and 23 protanopes) of middle European ancestry who possess multiple genes in the X-linked photopigment gene array. We have previously shown that only the first two genes of the array are expressed and contribute to the color vision phenotype. Therefore, the hypothesis is that the first two genes possessed by multigene-dichromats encode pigments of identical or nearly identical spectral sensitivity: one gene normal (R or G) and the other a hybrid (G/R or R/G). The spectral sensitivities of the encoded pigments were inferred from published in vitro and in vivo data. The color vision phenotype was assessed by standard anomaloscopy. Most genotypes (92%) included hybrid genes whose sequence and position and whose encoded pigment correlated exactly with the phenotype. However, one and possibly two of the protanopes had gene arrays consistent with protanomaly rather than protanopia, since two spectrally different pigments may be encoded by their arrays. Two of the deuteranopes had only R- and G-photopigment genes, without any detectable G/R-hybrid genes or any as-of-yet identified point mutation or coding/promoter sequence deletions. Further, an unexpectedly high number of multigene-deuteranopes (11%) had the C203R mutation in their most upstream G-pigment gene, suggesting a founder effect of middle European origin for this mutation. About half of the protanopes possessed an upstream R/G-hybrid gene with different exon 2 coding sequences than their downstream G-pigment gene(s), which is inconsistent with published data implying that a single amino acid substitution in exon 2 can confer red-green color discrimination capacity on multigene-protans by altering the optical density of the cones.