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CXCL12 is required for stirrup‐shaped stapes formation during mammalian middle ear development
Author(s) -
Ankamreddy Harinarayana,
Koo Heiyeun,
Lee Young Jae,
Bok Jinwoong
Publication year - 2020
Publication title -
developmental dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.634
H-Index - 141
eISSN - 1097-0177
pISSN - 1058-8388
DOI - 10.1002/dvdy.180
Subject(s) - stapes , malleus , ossicles , incus , stirrup , middle ear , anatomy , biology , inner ear , structural engineering , engineering
Abstract Background The mammalian middle ear comprises a chain of three ossicles—the malleus, incus, and stapes—each of which has a unique morphology for efficiently transmitting sound information. In particular, the stapes, which is attached to the inner ear, is stirrup‐shaped with a head and base connected by two crural arches, forming the stapedial foramen, through which the stapedial artery passes. However, how the stapes acquires this critical stirrup shape for association with the stapedial artery during development is not clear. Results C‐X‐C motif chemokine ligand 12 (CXCL12) is a chemoattractant essential for cellular movement and angiogenesis. In Cxcl12 −/− embryos, migration of neural crest cells into the prospective middle ear regions and their mesenchymal condensation to form the three ossicles proceed normally in correct alignment with each other and the inner ear. However, in the absence of CXCL12, the stapes loses its stirrup shape and instead exhibits a columnar shape lacking the crural arches and central hole. In addition, although the stapedial artery initially forms during early mesenchymal condensation of the stapes, it degenerates without CXCL12 function. Conclusion CXCL12 plays an essential role in establishing the stirrup‐shaped architecture of the stapes, possibly by maintaining the stapedial foramen and stapedial artery throughout development.