Gunther Karen L, Neitz Jay, Neitz Maureen
Department of Psychology, Wabash College, Crawfordsville, Indiana, USA.
Vis Neurosci. 2008 May-Jun;25(3):265-71. doi: 10.1017/S0952523808080280.
In support of the long-held idea that cone ratio is genetically determined by variation linked to the X-chromosome opsin gene locus, the present study identified nucleotide differences in DNA segments containing regulatory regions of the L and M opsin genes that are associated with significant differences in the relative number of L versus M cones. Specific haplotypes (combinations of genetic differences) were identified that correlated with high versus low L:M cone ratio. These findings are consistent with the biological principle that DNA sequence variations affect binding affinities for protein components of complexes that influence the relative probability that an L versus M opsin gene will be silenced during development, and in turn, produce variation in the proportion of L to M cones.
为支持长期以来的观点，即视锥细胞比例由与X染色体视蛋白基因位点相关的变异通过基因决定，本研究在包含L和M视蛋白基因调控区域的DNA片段中鉴定出核苷酸差异，这些差异与L视锥细胞和M视锥细胞相对数量的显著差异相关。鉴定出了与高L:M视锥细胞比例和低L:M视锥细胞比例相关的特定单倍型（基因差异组合）。这些发现与生物学原理一致，即DNA序列变异会影响复合物蛋白质成分的结合亲和力，而这些复合物会影响L视蛋白基因和M视蛋白基因在发育过程中被沉默的相对概率，进而导致L视锥细胞与M视锥细胞比例产生变化。
