An understanding of the morphogenesis and operation of hair cells requires identification of the genes expressed in these cells and of the functions of the cognate proteins. As an initial step towards this goal, we have used DNA-microarray technology to identify the transcripts present in hair cells of the adult zebrafish. After isolating pure populations of hair cells from the lagena of the inner ear, we amplified and labeled RNA and hybridized the resultant probes to oligonucleotide microarrays. To exclude genes expressed ubiquitously in epithelial cells, we conducted parallel experiments with hepatocytes and disregarded the genes that they expressed. The hair-cell transcriptome of the zebrafish includes genes involved in vesicle fusion, transcriptional regulation, and transmembrane ion movement;among these are homologs of genes that, when mutated, produce deafness in humans and mice. Additional genes encode proteins that are involved in cytoskeletal function, and might therefore contribute to the formation and maintenance of the hair bundle. These components include actin-binding and -capping proteins as well as constituents of the intraflagellar transport system. Finally, the transcriptional profile encompasses numerous genes of undetermined function. Using the molecular-biological techniques applicable to the zebrafish, we have begun to investigate the roles that some of these genes'products play in hair-bundle development.

Public Health Relevance

The hair cell is a mechanoreceptor of the inner ear and lateral-line system that is responsible for hearing, balance, and the detection of water movement by some aquatic vertebrates. The hair cell possesses a hair bundle, which holds the apparatus of mechanotransduction. To identify the protein constituents of the hair bundle and to give insights into hereditary deafness, we are developing a functional genomics approach in zebrafish.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
5R01DC009437-05
Application #
8473199
Study Section
Auditory System Study Section (AUD)
Program Officer
Freeman, Nancy
Project Start
2009-06-05
Project End
2014-05-31
Budget Start
2013-06-01
Budget End
2014-05-31
Support Year
5
Fiscal Year
2013
Total Cost
$360,943
Indirect Cost
$131,043
Name
Case Western Reserve University
Department
Otolaryngology
Type
Schools of Medicine
DUNS #
077758407
City
Cleveland
State
OH
Country
United States
Zip Code
44106
Antonellis, Patrick J; Pollock, Lana M; Chou, Shih-Wei et al. (2014) ACF7 is a hair-bundle antecedent, positioned to integrate cuticular plate actin and somatic tubulin. J Neurosci 34:305-12
Santos-Cortez, Regie Lyn P; Lee, Kwanghyuk; Azeem, Zahid et al. (2013) Mutations in KARS, encoding lysyl-tRNA synthetase, cause autosomal-recessive nonsyndromic hearing impairment DFNB89. Am J Hum Genet 93:132-40
Chou, Shih-Wei; Hwang, Philsang; Gomez, Gustavo et al. (2011) Fascin 2b is a component of stereocilia that lengthens actin-based protrusions. PLoS One 6:e14807