The mammalian middle ear comprises a chain of ossicles, the malleus, incus, and stapes that act as an impedance matching device during the transmission of sound from the tympanic membrane to the inner ear. These ossicles are derived from cranial neural crest cells that undergo endochondral ossification and subsequently differentiate into their final functional forms. Defects that occur during middle ear development can result in conductive hearing loss. In this review, we summarize studies describing the crucial roles played by signaling molecules such as sonic hedgehog, bone morphogenetic proteins, fibroblast growth factors, notch ligands, and chemokines during the differentiation of neural crest into the middle ear ossicles. In addition to these cell‐extrinsic signals, we also discuss studies on the function of transcription factor genes such as Foxi3, Tbx1, Bapx1, Pou3f4, and Gsc in regulating the development and morphology of the middle ear ossicles.

中文翻译：

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揭示调控哺乳动物中耳小骨发育的分泌信号和转录因子

哺乳动物中耳包括一系列听骨、锤骨、砧骨和镫骨，它们在声音从鼓膜到内耳的传输过程中充当阻抗匹配装置。这些小骨来源于颅神经嵴细胞，这些细胞经历软骨内骨化，随后分化为最终的功能形式。中耳发育过程中出现的缺陷会导致传导性听力损失。在这篇综述中，我们总结了一些研究，描述了信号分子在神经嵴分化为中耳小骨的过程中所起的关键作用，如音速刺猬蛋白、骨形态发生蛋白、成纤维细胞生长因子、缺口配体和趋化因子。除了这些细胞外信号外，我们还讨论了对转录因子基因功能的研究，例如Foxi3、Tbx1、Bapx1、Pou3f4和Gsc在调节中耳听小骨的发育和形态方面。