To investigate the relationship between light sensing systems in the eye and circadian oscillators in the hypothalamus of subterranean rodents, we studied subterranean Mandarin voles (Lasiopodomys mandarinus) that spend their entire lives under dark conditions with degenerated eyes, and compared oscillatory expression patterns of clock genes in the hypothalamus and eye between Mandarin voles and their aboveground relatives, Brandt's voles (L. brandtii). Individuals of both vole species were kept under a 12-h light/12-h dark condition or continuous dark condition for 4 weeks. In both species, the expressions of most genes showed significant cosine rhythmicity in the hypothalamus but relatively weak rhythmicity in the eye. The number of rhythmic genes in the eye of Mandarin voles increased under the dark condition, but the opposite trend was observed in the eye of Brandt's voles. The expression levels of most clock genes in the hypothalamus of both vole species did not significantly differ between the two conditions, but unlike in Mandarin voles, these expression levels significantly decreased in the eye of Brandt's voles kept under the dark condition. In both vole species, the peak phase of most clock genes exhibited advanced or invariant change in the hypothalamus under the dark condition, and the peak phase of most clock genes showed consistent changes between the eye and hypothalamus of Mandarin voles. However, most clock genes in the eye showed a delayed phase in Brandt's voles kept under the dark condition. In conclusion, the hypothalamus plays an important role in both vole species irrespective of the light condition. However, the expression patterns of clock genes in the eye differed between the vole species, indicating that each species adapted differently to their environments.

中文翻译：

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两种 Lasipodomys 物种下丘脑和眼睛中时钟基因的表达模式。

为了研究眼睛中的光感应系统与地下啮齿动物下丘脑昼夜节律振荡器之间的关系，我们研究了在黑暗条件下一生都在退化的眼睛下生活的地下普通田鼠 (Lasiopodomys mandarinus)，并比较了时钟基因的振荡表达模式在普通话田鼠与其地上亲戚布兰特田鼠（L.brandtii）之间的下丘脑和眼睛中。两种田鼠个体都在 12 小时光照/12 小时黑暗条件下或连续黑暗条件下保持 4 周。在这两个物种中，大多数基因的表达在下丘脑显示出显着的余弦节律性，但在眼睛中表现出相对较弱的节律性。在黑暗条件下，普通话田鼠眼中的节律基因数量增加，但是在布兰特的田鼠眼中观察到了相反的趋势。两种田鼠下丘脑中大多数时钟基因的表达水平在两种条件下没有显着差异，但与普通话田鼠不同的是，在黑暗条件下的布兰特田鼠眼中，这些表达水平显着降低。在两种田鼠物种中，在黑暗条件下，大多数时钟基因的峰值相位在下丘脑中表现出提前或不变的变化，并且大多数时钟基因的峰值相位在柑橘田鼠的眼睛和下丘脑之间表现出一致的变化。然而，眼睛中的大多数时钟基因在处于黑暗条件下的布兰特田鼠中显示出延迟阶段。总之，无论光照条件如何，下丘脑在两种田鼠中都起着重要作用。然而，