Department of Craniofacial Development and Stem Cell Biology, Kings College London, Guy's Tower, Guy's Hospital, London Bridge, London, UK.
Dev Dyn. 2012 Sep;241(9):1396-404. doi: 10.1002/dvdy.23831. Epub 2012 Aug 2.
The stapes, an ossicle found within the middle ear, is involved in transmitting sound waves to the inner ear by means of the oval window. There are several developmental problems associated with this ossicle and the oval window, which cause hearing loss. The developmental origin of these tissues has not been fully elucidated.
Using transgenic reporter mice, we have shown that the stapes is of dual origin with the stapedial footplate being composed of cells of both neural crest and mesodermal origin. Wnt1cre/Dicer mice fail to develop neural crest-derived cartilages, therefore, have no middle ear ossicles. We have shown in these mice the mesodermal stapedial footplate fails to form and the oval window is induced but underdeveloped.
If the neural crest part of the stapes fails to form the mesodermal part does not develop, indicating that the two parts are interdependent. The stapes develops tightly associated with the otic capsule, however, it is not essential for the positioning of the oval window, suggesting that other tissues, perhaps within the inner ear are needed for oval window placement.
镫骨是中耳内的一个小骨，通过卵圆窗将声波传递到内耳。这个小骨和卵圆窗与几种发育问题有关，这些问题会导致听力损失。这些组织的发育来源尚未完全阐明。
我们使用转基因报告小鼠表明，镫骨具有双重起源，其镫骨足板由神经嵴和中胚层来源的细胞组成。Wnt1cre/Dicer 小鼠不能发育出神经嵴衍生的软骨，因此没有中耳小骨。我们在这些小鼠中表明，中胚层的镫骨足板不能形成，卵圆窗被诱导但发育不良。
如果镫骨的神经嵴部分未能形成，中胚层部分就不会发育，表明这两部分是相互依存的。镫骨与耳囊紧密相关发育，但对于卵圆窗的定位并非必需，这表明其他组织，可能在内耳内，对于卵圆窗的定位是必要的。
