The primordial, blue-cone color system of the mouse retina
The primordial, blue-cone color system of the mouse retina
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DOI：
10.1523/jneurosci.1117-05.2005
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发表时间：
2005-06-01
影响因子：
5.3
通讯作者：
Euler, T
中科院分区：
文献类型：
--
作者：
Haverkamp, S;Wässle, H;Euler, T
人类和旧世界灵长类动物具有基于三种光谱类型的视锥细胞[长波长（L-）、中波长（M-）和短波长（S-）视锥细胞]的三色色觉。所有其他胎盘哺乳动物都是二色视者，它们的色觉依赖于L-和S-视锥信号的比较;然而，它们的视锥选择性视网膜回路仍然是未知的。在这里，我们确定了小鼠视网膜的S-视锥选择性（蓝锥）双极细胞。它们在表达Clomeleon的转基因小鼠中被标记，Clomeleon是一种氯敏感的荧光蛋白，在thy 1启动子的控制下。蓝视锥双极细胞仅占双极细胞群的1-2%，它们的树突选择性地接触表达S-视蛋白的视锥。在小鼠视网膜的背侧，只有3-5%的视锥表达S-视蛋白，并且它们都与蓝锥双极细胞接触，而所有表达L-视蛋白的视锥（类似于95%）都被避开。在小鼠腹侧视网膜中，绝大多数视锥细胞同时表达S-和L-视蛋白。它们不与蓝锥双极细胞接触。少数腹锥仅表达S-视蛋白，并且它们选择性地与蓝锥双极细胞接触。我们认为这些是真正的S锥。与其他的球果相反，它们的花梗只含有少量的球果抑制蛋白。小鼠视网膜的蓝锥双极细胞和它们的锥选择性与灵长类动物的蓝锥双极细胞非常相似，我们认为它们都代表了哺乳动物视网膜遗传学上古老的颜色系统。
Humans and old world primates have trichromatic color vision based on three spectral types of cone [long-wavelength (L-), middle-wavelength (M-), and short-wavelength (S-) cones]. All other placental mammals are dichromats, and their color vision depends on the comparison of L- and S- cone signals; however, their cone-selective retinal circuitry is still unknown. Here, we identified the S-cone-selective (blue cone) bipolar cells of the mouse retina. They were labeled in a transgenic mouse expressing Clomeleon, a chloride-sensitive fluorescent protein, under the control of the thy1 promoter. Blue-cone bipolar cells comprise only 1-2% of the bipolar cell population, and their dendrites selectively contact S-opsin-expressing cones. In the dorsal half of the mouse retina, only 3-5% of the cones express S-opsin, and they are all contacted by blue-cone bipolar cells, whereas all L-opsin-expressing cones (similar to 95%) are avoided. In the ventral mouse retina, the great majority of cones express both S- and L-opsin. They are not contacted by blue-cone bipolar cells. A minority of ventral cones express S-opsin only, and they are selectively contacted by blue-cone bipolar cells. We suggest that these are genuine S-cones. In contrast to the other cones, their pedicles contain only low amounts of cone arrestin. The blue-cone bipolar cells of the mouse retina and their cone selectivity are closely similar to primate blue-cone bipolars, and we suggest that they both represent the phylogenetically ancient color system of the mammalian retina.