Investigating the role of fgf13 in the statoacoustic ganglion morphogenesis in Danio rerio

Abstract

The statoacoustic ganglion (SAG) is the inner ear sensory ganglion, composed of bipolar neurons that send projections to the hair cells of the inner ear and the hindbrain. Fibroblast growth factor 13 (fgf13), a microtubule-stabilising protein, involved in axon branching and leading processes, is highly expressed in developing sensory neurons of the head. This research project examines the critical role of fgf13 paralogs (fgf13a and fgf13b) in early neuronal progenitor migration and axonogenesis in the zebrafish SAG, by evaluating morphological and axon formation variations in a double knockout (KO) stable line. Confocal imaging of Tg(neurod1:eGFP) / fgf13a/b KO zebrafish SAGs revealed no major morphological differences between mutants and control embryos, however previous results on F0 injected embryos showed SAG development impairment. Posteriorly, a quantitative real-time polymerase chain reaction (qRT-PCR) analysis of fgf12a/b mRNA expression showed no differences in the fgf12 mRNA expression, suggesting fgf12 is not responsible for the compensation on the KO line embryos. Due to compensation or other mechanisms, the study could not decipher the role due to limited fish breeding and time preparation of new experimental procedures. However, elucidation of the role of fgf13 could unravel the participation in understanding auditory disorders.