Zebrafish Anatomical Dictionary

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Structure description: ear

by Tanya Whitfield

Name: ear

Abbreviation: ov, ot, otc, oto

Synonyms: otic placode, otic vesicle, otic capsule, otocyst, inner ear

Figures:

4 day ear Staging series live whole-mounts

Staging series sections

5 day ear sections

3D movie of 5 day ear Z-section movie of 5 day ear

Description: : The auditory (hearing) and vestibular (balance) organ of the fish, equivalent to the inner ear of amniotes (fish do not have an outer or middle ear). Develops from a cranial ectodermal thickening, the otic placode, which arises on either side of the head midway between the eye and the first somite. This cavitates to form a simple vesicle, from which all structures of the inner ear (semicircular canals, sensory patches and neurons of the statoacoustic (VIIIth) ganglion) are thought to arise. Five sensory patches develop in the embryonic ear: three cristae (each associated with a semicircular canal) and two maculae (each associated with an otolith). Two further sensory patches, and one additional otolith, are present in the adult ear. Neuroblasts delaminate from the epithelium of the ventral floor of the otic vesicle to form the statoacoustic (VIIIth) ganglion between 22 and 42h. Epithelial projections forming the semicircular canal system protrude into the vesicle and fuse between 44 and 72h. A dorsolateral septum, dividing the anterior and posterior canals, grows into the ear during the same period.

Homologues:

• Human: otic placode, otic vesicle, inner ear
• Mouse: otic placode, otic vesicle, inner ear
• Chicken: otic placode, otic vesicle, inner ear
  
  
• Fish do not have a counterpart of the cochlea, the specialised auditory organ of amniotes, with its associated sensory patch (organ of Corti (mouse, human); basilar papilla (chick)). Instead, the macular organs of the sacculus, lagena and macula neglecta detect sound waves in the adult fish, in addition to their vestibular roles. The utriculus and cristae of the semicircular canals have the same vestibular functions in all species, detecting linear accelerations and gravity (utriculus) and angular accelerations (cristae).
• Frog: otic placode, otic vesicle, inner ear
• Fly: No direct counterparts. Hearing insects hear using auditory receptors (chordotonal sensilla, also known as scolopidia) associated with auditory (tympanal or flagellar) organs, which may be in a variety of anatomical locations. In Drosophila, Johnston's organs, found on the antennae, discriminate species-specific courtship songs. The halteres (reduced and specialised hind wings, rich in campaniform sensilla) function to maintain balance during flight and motion.

Stages:

• First appears at: placode: 9-14 somites
• Disappears (or changes name) at: placode begins to cavitate to form the otic vesicle at the18 somite stage

Parents (forms from): cranial placodal ectoderm (otic placode)

Children:

• Presumptive (thought to give rise to): Unknown
• Anlage (known to give rise to): ear (including sensory patches, semicircular canals, and otoliths), neurons of the statoacoustic (VIIIth) ganglion

Group (member of):

• Anatomical (group member): sensory systems
• Functional (group member): vestibular system

Markers:

• mRNA:
  

  bmp2b, bmp4, bmp7 (Chin et al., 1997; Dick et al., 2000; Lee et al., 1998; Martinez-Barberá et al., 1997)
  cdh1, cdh2, cdh11 (Franklin and Sargent, 1996)
  col2a1 (Lele and Krone, 1997)
  deltaA, deltaB, deltaD, serrateB (Haddon et al., 1998)
  dlx2, dlx3, dlx4, dlx6, dlx7 (Akimenko et al., 1994; Ekker et al., 1992; Ellies et al., 1997)
  emx2 (Morita et al., 1995)
  eya1 (Sahly et al., 1999)
  fgf8 (Reifers et al., 1998)
  hsp47 (Lele and Krone, 1997)
  kal1a, kal1b (Ardouin et al., 2000)
  msxc, msxd, msxe (Ekker et al., 1997; Ekker et al., 1992)
  otx1 (Li et al., 1995)
  pax2a, pax2b, pax5, pax8 (Krauss et al., 1991; Pfeffer et al., 1998)
  prox1 (Glasgow and Tomarev, 1998)
  rtk1 (Xu et al., 1996)
  sna2 (Thisse et al., 1995)
  tbx2b (Dheen et al., 1999)
  wnt4a (Blader et al., 1996)
  
  

• Antibodies:
  
  Pax2a (Riley et al., 1999)
  S100 zn1, zn5, zn15, zns2
  See also markers for sensory patches, hair cells and lateral line
  
  
• Other: None

Publications:

• Primary: Waterman, R. E., and Bell, D. H. (1984). Epithelial fusion during early semicircular canal formation in the embryonic zebrafish, Brachydanio rerio. Anatomical Record 210, 101-114.
• Secondary:
  Akimenko, M.-A., Ekker, M., Wegner, J., Lin, W., and Westerfield, M. (1994). Combinatorial expression of three zebrafish genes related to Distal-Less: Part of a homeobox gene code for the head. The Journal of Neuroscience 14, 3475-3486.

  Ardouin, O., Legouis, R., Fasano, L., David-Watine, B., Korn, H., Hardelin, J., and Petit, C. (2000). Characterization of the two zebrafish orthologues of the KAL-1 gene underlying X chromosome-linked Kallmann syndrome. Mechanisms of Development 90, 89-94.

  Blader, P., Strhäle, U., and Ingham, P. W. (1996). Three Wnt genes expressed in a wide variety of tissues during development of the zebrafish, Danio rerio: developmental and evolutionary perspectives. Development, Genes and Evolution 206, 3-13.

  Chin, A. J., Chen, J.-N., and Weinberg, E. S. (1997). Bone morphogenetic protein-4 expression characterizes inductive boundaries in organs of developing zebrafish. Development, Genes and Evolution 207, 107-114.

  Dheen, T., Slepstova-Friedrich, I., Xu, Y., Clark, M., Lehrach, H., Gong, Z., and Korzh, V. (1999). Zebrafish tbx-c functions during formation of midline structures. Development 126, 2703-2713.

  Dick, A., Hild, M., Bauer, H., Imai, Y., Maifeld, H., Schier, A. F., Talbot, W. S., Bouwmeester, T., and Hammerschmidt, M. (2000). Essential role of Bmp7 (snailhouse) and its prodomain in dorsoventral patterning of the zebrafish embryo. Development 127, 343-354.

  Ekker, M., Akimenko, M.-A., Allende, M. L., Smith, R., Drouin, G., Langille, R. M., Weinberg, E. S., and Westerfield, M. (1997). Relationships among msx gene structure and function in zebrafish and other vertebrates. Molecular Biology and Evolution 14, 1008-1022.

  Ekker, M., Akimenko, M.-A., Bremiller, R., and Westerfield, M. (1992). Regional expression of three homeobox transcripts in the inner ear of zebrafish embryos. Neuron 9, 27-35.

  Ellies, D. L., Stock, D. W., Hatch, G., Giroux, G., Weiss, K. M., and Ekker, M. (1997). Relationship between the genomic organisation and the overlapping embryonic expression patterns of the zebrafish dlx genes. Genomics 45, 580-590.

  Franklin, J. L., and Sargent, T. D. (1996). Ventral neural cadherin, a novel cadherin expressed in a subset of neural tissues in the zebrafish embryo. Developmental Dynamics 206, 121-130.

  Glasgow, E., and Tomarev, S. I. (1998). Restricted expression of the homeobox gene prox1 in developing zebrafish. Mechanisms of Development 76, 175-178.

  Haddon, C., Jiang, Y.-J., Smithers, L., and Lewis, J. (1998). Delta-Notch signalling and the patterning of sensory cell differentiation in the zebrafish ear: Evidence from the mindbomb mutant. Development 125, 4637-4644.

  Haddon, C., and Lewis, J. (1996). Early ear development in the embryo of the zebrafish, Danio rerio. Journal of Comparative Neurology 365, 113-123.

  Kimmel, C. B., Ballard, W. W., Kimmel, S. R., Ullmann, B., and Schilling, T. F. (1995). Stages of embryonic development of the zebrafish. Developmental Dynamics 203, 253-310.

  Kozlowski, D. J., Murakami, T., Ho, R. K., and Weinberg, E. S. (1997). Regional cell movement and tissue patterning in the zebrafish embryo revealed by fate mapping with caged fluorescein. Biochemistry and Cell Biology 75, 551-562.

  Krauss, S., Johansen, T., Korzh, V., and Fjose, A. (1991). Expression of the zebrafish paired box gene pax[zf-b] during early neurogenesis. Development 113, 1193-1206.

  Lee, K.-H., Marden, J. J., Thompson, M. S., Maclennan, H., Kishimoto, Y., Pratt, S. J., Schulte-Merker, S., Hammerschmidt, M., Johnson, S. L., Postlethwait, J. H., Beier, D. C., and Zon, L. I. (1998). Cloning and genetic mapping of zebrafish BMP-2. Developmental Genetics 23, 97-103.

  Lele, Z., and Krone, P. H. (1997). Expression of genes encoding the collagen-binding heat shock protein (Hsp47) and type II collagen in developing zebrafish embryos. Mechanisms of Development 61, 89-98.

  Li, Y., Allende, M. L., Finkelstein, R., and Weinberg, E. S. (1995). Expression of two zebrafish orthodenticle-related genes in the embryonic brain. Mechanisms of Development 48, 229-244.

  Malicki, J., Schier, A. F., Solnica-Krezel, L., Stemple, D. L., Neuhauss, S. C. F., Stainier, D. Y. R., Abdelilah, S., Rangini, Z., Zwartkruis, F., and Driever, W. (1996). Mutations affecting development of the zebrafish ear. Development 123, 275-283.

  Martnez-Barberá, J. P., Toresson, H., Da Rocha, S., and Krauss, S. (1997). Cloning and expression of three members of the zebrafish BMP family: Bmp2a, Bmp2b and Bmp4. Gene 198, 53-59.

  Morita, T., Nitta, H., Kiyama, Y., Mori, H., and Mishina, M. (1995). Differential expression of two zebrafish emx homeoprotein mRNAs in the developing brain. Neuroscience Letters 198, 131-134.

  Nicolson, T., Rüsch, A., Friedrich, R. W., Granato, M., Ruppersberg, J. P., and Nüsslein-Volhard, C. (1998). Genetic analysis of vertebrate sensory hair cell mechanosensation: the zebrafish circler mutants. Neuron 20, 271-283.

  Pfeffer, P. L., Gerster, T., Lun, K., Brand, M., and Busslinger, M. (1998). Characterization of three novel members of the zebrafish Pax2/5/8 family: dependency of Pax5 and Pax8 expression on the Pax2.1 (noi) function. Development 125, 3063-3074.

  Platt, C. (1993). Zebrafish inner ear sensory surfaces are similar to those in goldfish. Hearing Research 65, 133-140.

  Reifers, F., Bohli, H., Walsh, E. C., Crossley, P. H., Stainier, D. Y. R., and Brand, M. (1998). Fgf8 is mutated in zebrafish acerebellar (ace) mutants and is required for maintenance of midbrain-hindbrain boundary development and somitogenesis. Development 125, 2381-2396.

  Riley, B. B., Chiang, M.-Y., Farmer, L., and Heck, R. (1999). The deltaA gene of zebrafish mediates lateral inhibition of hair cells in the inner ear and is regulated by pax2.1. Development 126, 5669-5678.

  Sahly, I., Andermann, P., and Petit, C. (1999). The zebrafish eya1 gene and its expression pattern during embryogenesis. Development, Genes and Evolution 209, 399-410.

  Thisse, C., Thisse, B., and Postlethwait, J. H. (1995). Expression of snail2, a second memeber of the zebrafish snail family, in cephalic mesendoderm and presumptive neural crest of wild-type and spadetail mutant embryos. Developmental Biology 172, 86-99.

  Whitfield, T. T., Granato, M., van Eeden, F. J. M., Schach, U., Brand, M., Furutani-Seiki, M., Haffter, P., Hammerschmidt, M., Heisenberg, C.-P., Jiang, Y.-J., Kane, D. A., Kelsh, R. N., Mullins, M. C., Odenthal, J., and Nüsslein-Volhard, C. (1996). Mutations affecting development of the zebrafish inner ear and lateral line. Development 123, 241-254.

  Xu, Q., Alldus, G., Holder, N., and Wilkinson, D. G. (1996). Expression of truncated Sek-1 receptor tyrosine kinase disrupts the segmental restriction of gene expression in the Xenopus and zebrafish hindbrain. Development 121, 4005-4016.
  

Comments: Gene expression database: http://www.ihr.mrc.ac.uk/hereditary/genetable/index.shtml

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