POLYMORPHISM IN THE NUMBER OF GENES ENCODING LONG-WAVELENGTH-SENSITIVE CONE PIGMENTS AMONG MALES WITH NORMAL COLOR-VISION
POLYMORPHISM IN THE NUMBER OF GENES ENCODING LONG-WAVELENGTH-SENSITIVE CONE PIGMENTS AMONG MALES WITH NORMAL COLOR-VISION
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DOI：
10.1016/0042-6989(95)00008-n
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发表时间：
1995-09-01
期刊：
影响因子：
1.8
通讯作者：
GRISHOK, A
中科院分区：
文献类型：
--
作者：
NEITZ, M;NEITZ, J;GRISHOK, A
通过对27名色觉正常的男性的X连锁视色素基因进行直接DNA序列分析的检查显示，几乎一半的人具有两个或更多编码长波长敏感视锥色素的不同基因。这与Southern杂交研究结果提出的每个X染色体有一个长波色素基因的传统理论相反。此外，X连锁色素基因阵列的序列和结构的考虑表明，大多数观察者（多达2/3）具有像那些被提出为颜色异常的基础的杂交（或融合）基因。在一些观察者中，长波杂合基因含有大量的中波序列，例如，五个观察者具有含有包括外显子4的中波序列的杂合长波基因。这五个人中有三个人的杂交基因是他们唯一的长波基因，因此没有其他可能编码长波色素的基因。在这些受试者中，正是杂交基因产生了他们正常的长波敏感锥色素。杂交基因的高频率表明它们是长波基因的正常变异形式。与通常认为的相反，杂交基因的引入和表达不足以导致色觉缺陷。
Examination by direct DNA sequence analysis of the X-linked visual pigment genes in 27 males with normal color vision reveals that almost half have two or more different genes encoding a long-wavelength-sensitive cone pigment. This is counter to the conventional theory proposed from results of Southern hybridization studies that there is a single long-wave pigment gene per X-chromosome, Further, the sequences and consideration of the structure of the X-linked pigment gene array suggest that the majority of the observers (as many as 2/3) have hybrid (or fusion) genes like those that have been proposed to underlie color anomaly. In some observers the long-wave hybrid genes contain a substantial amount of middle-wave sequence, e.g. five observers have hybrid long-wave genes that contain middle-wave sequences that include exon 4. Three of those five have the hybrid as their only long-wave gene, and thus have no other gene that could potentially encode a long-wave pigment, In these subjects, it is the hybrid gene that produces their normal long-wavelength-sensitive cone pigment. The high frequency of hybrid genes indicates that they are normal variant forms of the long-wave gene. Contrary to what is commonly believed, the introduction and the expression of hybrid genes is not sufficient to cause color vision defects.