Abstract
The stereocilia on each hair cell are arranged into rows of ascending height, resulting in what we refer to as a "staircase-like" profile. At the proximal end of the cochlea the length of the tallest row of stereocilia in the staircase is 1.5 micron, with the shortest row only 0.3 micron. As one proceeds towards the distal end of the cochlea the length of the stereocilia progressively increases so that at the extreme distal end the length of the tallest row of the staircase is 5.5 micron and the shortest row is 2 micron. During development hair cells form their staircases in four phases of growth separated from each other by developmental time. First, stereocilia sprout from the apical surfaces of the hair cells (8-10-d embryos). Second (10-12-d embryos), what will be the longest row of the staircase begins to elongate. As the embryo gets older successive rows of stereocilia initiate elongation. Thus the staircase is set up by the sequential initiation of elongation of stereociliary rows located at increased distances from the row that began elongation. Third (12-17-d embryos), all the stereocilia in the newly formed staircase elongate until those located on the first step of the staircase have reached the prescribed length. In the final phase (17-d embryos to hatchlings) there is a progressive cessation of elongation beginning with the shortest step and followed by taller and taller rows with the tallest step stopping last. Thus, to obtain a pattern of stereocilia in rows of increasing height what transpires are progressive go signals followed by a period when all the stereocilia grow and ending with progressive stop signals. We discuss how such a sequence could be controlled.
Full Text
The Full Text of this article is available as a PDF (5.4 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bryan J., Kurth M. C. Actin-gelsolin interactions. Evidence for two actin-binding sites. J Biol Chem. 1984 Jun 25;259(12):7480–7487. [PubMed] [Google Scholar]
- Cooper J. A., Blum J. D., Pollard T. D. Acanthamoeba castellanii capping protein: properties, mechanism of action, immunologic cross-reactivity, and localization. J Cell Biol. 1984 Jul;99(1 Pt 1):217–225. doi: 10.1083/jcb.99.1.217. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Harris H. E., Weeds A. G. Plasma gelsolin caps and severs actin filaments. FEBS Lett. 1984 Nov 19;177(2):184–188. doi: 10.1016/0014-5793(84)81280-6. [DOI] [PubMed] [Google Scholar]
- Hasegawa T., Takahashi S., Hayashi H., Hatano S. Fragmin: a calcium ion sensitive regulatory factor on the formation of actin filaments. Biochemistry. 1980 Jun 10;19(12):2677–2683. doi: 10.1021/bi00553a021. [DOI] [PubMed] [Google Scholar]
- Hosoya H., Mabuchi I. A 45,000-mol-wt protein-actin complex from unfertilized sea urchin egg affects assembly properties of actin. J Cell Biol. 1984 Sep;99(3):994–1001. doi: 10.1083/jcb.99.3.994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hudspeth A. J. The cellular basis of hearing: the biophysics of hair cells. Science. 1985 Nov 15;230(4727):745–752. doi: 10.1126/science.2414845. [DOI] [PubMed] [Google Scholar]
- Liberman M. C., Dodds L. W. Acute ultrastructural changes in acoustic trauma: serial-section reconstruction of stereocilia and cuticular plates. Hear Res. 1987;26(1):45–64. doi: 10.1016/0378-5955(87)90035-9. [DOI] [PubMed] [Google Scholar]
- Mooseker M. S. Organization, chemistry, and assembly of the cytoskeletal apparatus of the intestinal brush border. Annu Rev Cell Biol. 1985;1:209–241. doi: 10.1146/annurev.cb.01.110185.001233. [DOI] [PubMed] [Google Scholar]
- Pickles J. O., Comis S. D., Osborne M. P. Cross-links between stereocilia in the guinea pig organ of Corti, and their possible relation to sensory transduction. Hear Res. 1984 Aug;15(2):103–112. doi: 10.1016/0378-5955(84)90041-8. [DOI] [PubMed] [Google Scholar]
- Pollard T. D., Cooper J. A. Actin and actin-binding proteins. A critical evaluation of mechanisms and functions. Annu Rev Biochem. 1986;55:987–1035. doi: 10.1146/annurev.bi.55.070186.005011. [DOI] [PubMed] [Google Scholar]
- Southwick F. S., DiNubile M. J. Rabbit alveolar macrophages contain a Ca2+-sensitive, 41,000-dalton protein which reversibly blocks the "barbed" ends of actin filaments but does not sever them. J Biol Chem. 1986 Oct 25;261(30):14191–14195. [PubMed] [Google Scholar]
- Tilney L. G., DeRosier D. J. Actin filaments, stereocilia, and hair cells of the bird cochlea. IV. How the actin filaments become organized in developing stereocilia and in the cuticular plate. Dev Biol. 1986 Jul;116(1):119–129. doi: 10.1016/0012-1606(86)90048-5. [DOI] [PubMed] [Google Scholar]
- Tilney L. G., Fukui Y., DeRosier D. J. Movement of the actin filament bundle in Mytilus sperm: a new mechanism is proposed. J Cell Biol. 1987 Apr;104(4):981–993. doi: 10.1083/jcb.104.4.981. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tilney L. G., Saunders J. C. Actin filaments, stereocilia, and hair cells of the bird cochlea. I. Length, number, width, and distribution of stereocilia of each hair cell are related to the position of the hair cell on the cochlea. J Cell Biol. 1983 Mar;96(3):807–821. doi: 10.1083/jcb.96.3.807. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tilney L. G., Saunders J. C., Egelman E., DeRosier D. J. Changes in the organization of actin filaments in the stereocilia of noise-damaged lizard cochleae. Hear Res. 1982 Jul;7(2):181–197. doi: 10.1016/0378-5955(82)90013-2. [DOI] [PubMed] [Google Scholar]
- Tilney L. G., Tilney M. S., Saunders J. S., DeRosier D. J. Actin filaments, stereocilia, and hair cells of the bird cochlea. III. The development and differentiation of hair cells and stereocilia. Dev Biol. 1986 Jul;116(1):100–118. doi: 10.1016/0012-1606(86)90047-3. [DOI] [PubMed] [Google Scholar]
- Tilney M. S., Tilney L. G., DeRosier D. J. The distribution of hair cell bundle lengths and orientations suggests an unexpected pattern of hair cell stimulation in the chick cochlea. Hear Res. 1987;25(2-3):141–151. doi: 10.1016/0378-5955(87)90087-6. [DOI] [PubMed] [Google Scholar]
- Wang L. L., Spudich J. A. A 45,000-mol-wt protein from unfertilized sea urchin eggs severs actin filaments in a calcium-dependent manner and increases the steady-state concentration of nonfilamentous actin. J Cell Biol. 1984 Sep;99(3):844–851. doi: 10.1083/jcb.99.3.844. [DOI] [PMC free article] [PubMed] [Google Scholar]