Atoh8, also named Math6, is a bHLH gene reported to have important functions in the developing nervous system, pancreas and kidney. However, the expression pattern and function of Atoh8 in the inner ear are still unclear. To study the function of Atoh8 in the developing mouse inner ear, we performed targeted deletion of Atoh8 by intercrossing Atoh8^lacZ/+ mice. We studied the expression pattern of Atoh8 in the inner ear and found interesting results that Atoh8-null (Atoh8^lacZ/lacZ) mice were viable but smaller than their littermates and they were severely hearing impaired, which was confirmed by hearing tests (ABR, DPOAE). We collected 129 viable newborns from 18 litters by crossing Atoh8^lacZ/+ mice and found that the distributions of Atoh8^lacZ/+, Atoh8^lacZ/lacZ and wild type were very close to their expected Mendelian ratio by χ² testing. However, no remarkable morphological changes in cochleae in mutant mice were detected under plastic sectioning and electron microscopy. No remarkable differences in the expression of Myosin6, Prestin, TrkC, GAD65, Tuj1, or Calretinin were detected between the mutant mice and the control mice. These findings indicate that Atoh8 plays an important role in the development of normal hearing, while further studies are required to elucidate its exact function in hearing.

中文翻译：

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Atoh8的靶向缺失导致小鼠严重听力损失

Atoh8，也称为Math6，是一种 bHLH 基因，据报道在发育中的神经系统、胰腺和肾脏中具有重要功能。然而，Atoh8在内耳中的表达模式和功能仍不清楚。为了研究 Atoh8 在发育中的小鼠内耳中的功能，我们通过交叉Atoh8 ^lacZ/+小鼠对Atoh8进行了靶向缺失。我们研究了Atoh8在内耳中的表达模式，发现有趣的结果是Atoh8 -null ( Atoh8 ^lacZ/lacZ) 小鼠可以存活，但比它们的同窝小鼠小，而且它们的听力严重受损，听力测试 (ABR、DPOAE) 证实了这一点。我们通过杂交Atoh8 ^lacZ/+小鼠从 18 窝中收集了 129 只存活新生儿，通过^χ2检验发现Atoh8 ^lacZ/+、Atoh8 ^lacZ/lacZ和野生型的分布非常接近其预期的孟德尔比率。然而，在塑料切片和电子显微镜下未检测到突变小鼠耳蜗的显着形态变化。在突变小鼠和对照小鼠之间未检测到 Myosin6、Prestin、TrkC、GAD65、Tuj1 或 Calretinin 的表达存在显着差异。这些发现表明Atoh8在正常听力的发展中起着重要作用，而需要进一步研究来阐明其在听力中的确切功能。