Ryan Allen F, Ikeda Ryoukichi, Masuda Masatsugu
Departments of Surgery/Otolaryngology, University of California, San Diego - School of Medicine, 9500 Gilman Drive, La Jolla, CA 92093, USA; Departments of Neurosciences, University of California, San Diego - School of Medicine, 9500 Gilman Drive, La Jolla, CA 92093, USA.
Departments of Surgery/Otolaryngology, University of California, San Diego - School of Medicine, 9500 Gilman Drive, La Jolla, CA 92093, USA.
Hear Res. 2015 Nov;329:33-40. doi: 10.1016/j.heares.2014.12.013. Epub 2015 Jan 21.
No genes have been discovered for which expression is limited only to inner ear hair cells. This is hardly surprising, since the number of mammalian genes is estimated to be 20-25,000, and each gene typically performs many tasks in various locations. Many genes are expressed in inner ear sensory cells and not in other cells of the labyrinth. However, these genes are also expressed in other locations, often in other sensory or neuronal cell types. How gene transcription is directed specifically to hair cells is unclear. Key transcription factors that act during development can specify cell phenotypes, and the hair cell is no exception. The transcription factor ATOH1 is well known for its ability to transform nonsensory cells of the developing inner ear into hair cells. And yet, ATOH1 also specifies different sensory cells at other locations, neuronal phenotypes in the brain, and epithelial cells in the gut. How it specifies hair cells in the inner ear, but alternate cell types in other locations, is not known. Studies of regulatory DNA and transcription factors are revealing mechanisms that direct gene expression to hair cells, and that determine the hair cell identity. The purpose of this review is to summarize what is known about such gene regulation in this key auditory and vestibular cell type.
尚未发现仅在内耳毛细胞中表达的基因。这并不奇怪，因为据估计哺乳动物基因的数量为20000 - 25000个，而且每个基因通常在不同位置执行多种任务。许多基因在内耳感觉细胞中表达，而不在迷路的其他细胞中表达。然而，这些基因也在其他位置表达，通常在其他感觉或神经元细胞类型中表达。基因转录如何特异性地导向毛细胞尚不清楚。在发育过程中起作用的关键转录因子可以确定细胞表型，毛细胞也不例外。转录因子ATOH1因其能够将发育中的内耳非感觉细胞转化为毛细胞而闻名。然而，ATOH1也在其他位置确定不同的感觉细胞、大脑中的神经元表型以及肠道中的上皮细胞。它如何在内耳中确定毛细胞，但在其他位置确定其他细胞类型，尚不清楚。对调控DNA和转录因子的研究正在揭示将基因表达导向毛细胞并确定毛细胞身份的机制。本综述的目的是总结关于这种关键听觉和前庭细胞类型中基因调控的已知情况。
