TABLE 1.
Anatomical features of the X. laevis inner ear during development
| Stage | Inner ear size1 μm | Landmark morphological characteristics [Key behaviors] |
|---|---|---|
| S28 | 60 ± 10 | otic vesicle [embryos lie along horizontal axis; body twitches] |
| S31 | 90 ± 10 | otic vesicle; pars inferior; sensory ganglion; stereociliary bundles |
| S37 | 130 ± 20 | otic vesicle; pars inferior; endolymphatic duct; sensory ganglion; stereociliary bundles [hatchlings attach to surfaces by mucus from cement gland and hang along vertical axis] |
| S42 | 180 ± 30 | Initial invaginations of otic vesicle (horizontal canal formation); pars inferior; pars superior; endolymphatic duct; cartilage; sensory ganglion; stereociliary bundles |
| S45 | 230 ± 30 | increased invagination of otic vesicle (formation of semicircular canals); pars inferior (saccular macula); pars superior; endolymphatic duct; cartilage; sensory ganglion; stereociliary bundles [larvae feed] |
| S47 | 540 ± 40 | sacculus; utricle; horizontal canal; anterior canal; posterior canal; lagena; endolymphatic duct; cartilage; otoconia; sensory ganglion; stereociliary bundles |
| S50 | 1080 ± 90 | sacculus; utricle; horizontal canal; anterior canal; posterior canal; lagena; amphibian papilla; basilar papilla; endolymphatic duct; cartilage, otoconia; sensory ganglion; stereociliary bundles |
1
Size estimated in the anteroposterior dimension by multiplying the total number of sections by the thickness of sections in paraffin embedded tissue (mean ± S.D.; n = 3 for all stages). Actual size may be larger due to shrinkage artifacts incurred during tissue processing.