Is Essential for Hair Cell Morphogenesis and Auditory Function in Zebrafish.

Hereditary hearing loss caused by defective hair cells is one of the most common congenital diseases, whose nosogenesis is still unclear because many of the causative genes remain unidentified. Claudins are one kind of transmembrane proteins that constitute the most important components of the tight junctions and paracellular barrier and play important roles in neurodevelopment. In this study, we investigated the function of in morphogenesis and auditory function of the hair cell in zebrafish. The results of hybridization showed that was specifically localized in the otic vesicle and neuromasts in zebrafish embryos. The deficiency of caused significant reduction of otic vesicle size and loss of utricle otolith. Moreover, the startle response and vestibulo-ocular reflex experiments revealed that loss of led to serious hearing loss and vestibular dysfunction. Importantly, the confocal microscopy observation found that compared to the control zebrafish, the morphants and mutants displayed significantly reduced the number of cristae hair cells and shortened kinocilia. Besides, the deficiency of also caused the loss of hair cells in neuromasts which could be rescued by injecting mRNA into the mutant embryos at one cell stage. Furthermore, the immunohistochemistry experiments demonstrated remarkable apoptosis of hair cells in the neuromasts, which might contribute to the loss of hair cells number. Overall, these data indicated that is indispensable for the development of hair cells, vestibular function, and hearing ability of zebrafish.