Yamaguchi T, Motulsky A G, Deeb S S
Department of Medicine, University of Washington, Seattle 98195, USA.
Hum Mol Genet. 1997 Jul;6(7):981-90. doi: 10.1093/hmg/6.7.981.
We determined the genotypes of the X-chromosome-linked red/green color vision genes by a novel PCR/SSCP-based method and assessed expression by mRNA analysis in retinae of 51 unselected post mortem eye specimens from Caucasian males of unknown color vision status. All individuals had a single red (long-wave) pigment gene and one or more (an average of two) green (middle-wave) pigment genes. Four males had 5'green-red3' hybrid genes in addition to normal red and green pigment genes. These findings are consistent with earlier studies on human visual pigment gene structure using Southern blotting and with a recent study using pulsed-field electrophoresis. We interpret claims of much larger numbers of red, green and green-red hybrid genes to be technical artifacts. The ratio of expressed red to green pigment retinal mRNA varied widely (1-10 with a mode of 4) and was not correlated with that of red to green pigment genes. In one individual with a green-red hybrid gene in addition to normal red and green pigment genes, the normal red pigment gene and the hybrid gene were both expressed, but the normal green gene was not. This person presumably had deuteranomalous color vision. Two with green-red hybrid genes expressed the normal red and green pigment genes, but not the hybrid genes. These two individuals presumably had normal color vision. We interpret the failure to express their green-red hybrid genes to be caused by their location at a more distal position in the visual pigment gene array.
我们采用一种基于聚合酶链反应/单链构象多态性的新方法，确定了X染色体连锁的红/绿色觉基因的基因型，并通过mRNA分析，对51份来自色觉状况未知的高加索男性的未经挑选的死后眼标本视网膜中的基因表达进行了评估。所有个体都有一个红色（长波）色素基因和一个或多个（平均两个）绿色（中波）色素基因。4名男性除了正常的红色和绿色色素基因外，还有5'绿色-红色3'杂种基因。这些发现与早期使用Southern印迹法对人类视觉色素基因结构的研究以及最近使用脉冲场电泳的研究结果一致。我们认为关于存在大量红色、绿色和绿色-红色杂种基因的说法是技术假象。视网膜中表达的红色与绿色色素mRNA的比例差异很大（1至10，众数为4），且与红色与绿色色素基因的比例无关。在一名除了正常的红色和绿色色素基因外还有一个绿色-红色杂种基因的个体中，正常的红色色素基因和杂种基因都有表达，但正常的绿色基因没有表达。这个人可能患有绿色异常型色觉障碍。两名有绿色-红色杂种基因的个体表达了正常的红色和绿色色素基因，但没有表达杂种基因。这两个人可能色觉正常。我们认为他们的绿色-红色杂种基因未能表达是由于其在视觉色素基因阵列中位于更远端的位置所致。
