Journal
DEVELOPMENTAL BIOLOGY
Volume 231, Issue 2, Pages 410-419Publisher
ACADEMIC PRESS INC
DOI: 10.1006/dbio.2001.0154
Keywords
middle ear; mammals; ossicles; tympanic membrane; signalling; patterning
Categories
Ask authors/readers for more resources
The middle ear allows animals to hear while moving in an aerial medium. It is composed of a cavity harbouring a chain of three ossicles that transmit vibrations produced by airborne sound in the tympanic membrane into the inner ear, where they are converted into neural impulses. The middle ear develops in the branchial arches, and this requires sequential interactions between the epithelia and the underlying mesenchyme. Gene-inactivation experiments have identified genes required for the formation of different middle ear components. Some encode for signalling molecules, including Endothelin1 and Egf8, probable mediators of epithelial-mesenchymal interactions. Other genes, including Eya1, Prx1, Hoxa1, Hoxa2, D1x1, D1x2, D1x5, and Gsc, are most likely involved in patterning and morphogenetic processes in the neural crest-derived mesenchyme. Mechanisms controlling formation of a functional tympanic membrane are also discussed. Basically, the tympanic ring, which serves as support for the tympanic membrane, directs invagination of the first pharingeal cleft ectoderm to form the external acoustic meatus (EAM), which provides the outer layer of the membrane. Gsc and Prx1 are essential for tympanic ring development. While invaginating, the EAM controls skeletogenesis in the underlying mesenchyme to form the manubrium of the malleus, the link between the membrane and the middle ear ossicles. (C) 2001 Academic Press.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available