Zebrafish

Summary of the article Cilia-Associated Genes Play Differing Roles in Aminoglycoside-Induced Hair Cell Death in Zebrafish. Stawicki TM, Hernandez L, Esterberg R, Linbo T, Owens KN, Shah AN, Thapa N, Roberts B, Moens CB, Rubel EW, Raible DW. G3 (Bethesda). 2016 Jul 7;6(7):2225-35. doi: 10.1534/g3.116.030080. PMID: 27207957 Free PMC article.  https://pubmed.ncbi.nlm.nih.gov/27207957/

Zebrafish are used as an in vivo model for research on human diseases and brain development. At the industrial level, zebrafish are also used as a model to test new drugs and chemical toxicity.

Hair cells are located inside the ear. They are sensors that convert mechanical stimuli evoked by sound and head movements into electrical signals transmitted to the brain. Hair cells have one cilium, which is a thin, short, and microscopic hairlike structure that vibrates in response to stimuli.

Several diseases, called ciliopathies, are associated with gene mutations related to the cilia structures. Ciliopathies can affect entire organs, causing shortening of bones, retinal degeneration, or deafness.

A category of antibiotics, called aminoglycoside antibiotics, can induce hair cell death and may also cause hearing loss in some patients. 

This study focused on understanding how some genes affect the functions of hair cells. For that, the researchers used zebrafish as a model to test mutations (changes) in specific genes, implicated in the transport of molecules within the cilia. The transport of molecules, mostly proteins, forms and maintains the cilia on the surface of the cells.

The researchers found that mutations on some cilia genes implicated in the transport of proteins made the hair cells resistant to aminoglycoside antibiotics, preventing their death. In some, but not all cases, this resistance appeared to be due to changes in how the hair cells functioned. This suggests the cilia or cilia genes may play a role in both general hair cell function and how these antibiotics kill hair cells.