Three-Dimensional Reconstruction of C57BL/6 Mouse Inner Ear during Development

Abstract

Purpose: To explore the three-dimensional (3-D) morphological characteristics of the complicated inner ear development of the C57BL/6 mouse. Methods: Specimens of C57BL/6 mouse embryos on days E7.5, E8.5, E9.5, E10.5, E11.5, E12.5 and E14.5 were collected and sectioned serially in this experiment. After hematoxylin and eosin staining, parts of the inner ear were pictured under the microscope with specific positional control. Using the protocol of 3D-DOCTOR software, we outlined the inner ear margin including the inner and extra face in different colors and put them into the 3-D program to reconstruct the 3-D model. Results: 3-D models of the E9.5, E10.5, E11.5, E12.5 and E14.5 inner ear were obtained and proved to be fine. Different parts of the inner ear were shown clearly in different colors in the 3-D model and significant morphological changes of the inner ear were shown during development between E9.5 and E14.5. Conclusion: The new technology of 3-D reconstruction is a useful and important tool to directly observe the complex development of the inner ear, and the development between E9.5 and E14.5 has been proved by the 3-D model to be the most complex and important period of the development of the C57BL/6 mouse inner ear.

De novo variants in GREB1L are associated with non-syndromic inner ear malformations and deafness

“…We found that Greb1l expression is widespread, and not highly compartmentalized during craniofacial development, and peaks at E8.5 and E13–E16, after which it declines during adulthood (Fig 2). In mice, the inner ear rises from a thickening of the ectoderm known as the otic placode at E7.5, and at E8.5 the otic placode invaginates to form the otocyst (Chi et al 2009). At E9.5, the otocyst has closed and from here on to E14.5, complex and rapid morphological changes occur.…”

“…During this time-frame the mature inner ear structure is formed, which is comprised of the semicircular canals, vestibule, and cochleae. At E12.5, all primordial structures have undergone further refinements, approximating their mature shape, and at E14.5, the membranous labyrinth has attained its mature shape, and the cochlea has reached one and a half turns (Chi et al 2009). We show that Greb1l peaks in the very early development of the inner ear (E8.5 otic placode invagination), later in the maturing and the refinement of the formed cochlear, and vestibular shapes (E13–E16), supporting a possibly important role in early ear development.…”