Abstract：
The inner ear of mammals includes the cochlea and vestibule, which house specialized hair cells that are responsible for hearing and balance, respectively. While cochlear hair cells fail to regenerate following damage, those of the utricle, which is part of the vestibular apparatus, show partial regeneration. In birds, the macula lagena, a unique ear structure in this clade, has the ability to regenerate hair cells similarly to the utricle. Many studies have sought to explain regeneration in terms of evolution and species differences. However, it remains unclear what the cellular and molecular basis is behind the differences in inner ear structures and between avians and mammals. In the present study, we first investigated the anatomical structures of the inner ear of both chickens and rodents. We then performed RNA sequencing (RNA-Seq) and made cross-species analyses of the expression of homologous genes obtained from the inner ear tissue from both chickens and mice. Finally, we focused on the lagena, the basilar papilla, and the utricle in chickens and identified differentially expressed genes between tissues and determined the expression patterns of genes involved in inner ear structure formation by single-cell RNA sequencing and bulk RNA-Seq. We concluded that the cellular and molecular composition of the lagena is more similar to that of the utricle than the cochlea. Taken together, our study provides a valuable resource for the study of inner ear evolution and development.
摘要：
哺乳动物的内耳包括耳蜗和前庭,容纳负责听觉和平衡的特殊毛细胞，分别。虽然耳蜗毛细胞在损伤后无法再生，那些墨镜，它是前庭器官的一部分，显示部分再生。在鸟类中，黄斑鱼，这个进化枝独特的耳朵结构，具有再生毛细胞的能力，类似于细胞。许多研究试图从进化和物种差异的角度解释再生。然而,目前尚不清楚内耳结构以及禽类和哺乳动物之间的差异背后的细胞和分子基础是什么。在本研究中,我们首先研究了鸡和啮齿动物内耳的解剖结构。然后，我们进行了RNA测序（RNA-Seq），并对从鸡和小鼠的内耳组织获得的同源基因的表达进行了跨物种分析。最后,我们专注于Lagena,基底乳头,和鸡的胞囊，并鉴定了组织之间的差异表达基因，并通过单细胞RNA测序和批量RNA-Seq确定了与内耳结构形成有关的基因的表达模式。我们得出的结论是，lagena的细胞和分子组成与耳蜗的细胞和分子组成更相似。一起来看,我们的研究为内耳进化和发育的研究提供了宝贵的资源。
