Contributions of mirror-image hair cell orientation to mouse otolith organ and zebrafish neuromast function: Part 1/2, Zebrafish data

Otolith organs in the inner ear and neuromasts in the fish lateral-line harbor two populations of hair cells oriented to detect stimuli in opposing directions. The underlying mechanism is highly conserved: the transcription factor EMX2 is regionally expressed in just one hair cell population and acts through the receptor GPR156 to reverse cell orientation relative to the other population. In mouse and zebrafish, loss of Emx2 results in sensory organs that harbor only one hair cell orientation and are not innervated properly. In zebrafish, Emx2 also confers hair cells with reduced mechanosensory properties. Here, we leverage mouse and zebrafish models lacking GPR156 to determine how detecting stimuli of opposing directions serves vestibular function, and whether GPR156 has other roles besides orienting hair cells. We find that otolith organs in Gpr156 mouse mutants have normal zonal organization and normal type I-II hair cell distribution and mechano-electrical transduction properties. I..., Zebrafish immunofluorescence and imaging (Figures 5, Figures 9-10)
Immunohistochemistry was performed on whole larvae at 5 dpf. Whole larvae were fixed with 4% paraformaldehyde in PBS at 4°C for 3.5 hr. For pre- and post-synaptic labeling all wash, block and antibody solutions were prepared with 0.1% Tween in PBS (PBST). For Emx2 labeling performed on sparse afferent labeling (see below) all wash, block and antibody solutions were prepared with PBS + 1% DMSO, 0.5% Triton-X100, 0.1% Tween-20 (PBDTT). After fixation, larvae were washed 4 × 5 min in PBST or PBDTT. For synaptic labeling, larvae were permeabilized with Acetone. For this permeabilization larvae were washed for 5 min with H2O. The H2O was removed and replaced with ice-cold acetone and placed at −20°C for 5 min, followed by a 5 min H2O wash. The larvae were then washed for 4 × 5 min in PBST. For all immunostains larvae were blocked overnight at 4°C in blocking solution (2% goat serum, 1% bovine serum albumin, 2% fish skin gelat..., , # Data from: Contributions of mirror-image hair cell orientation to mouse otolith organ and zebrafish neuromast function

Summary

Paper associated with dataset:

eLife (2024)

[https://doi.org/10.7554/eLife.97674.1](https://doi.org/10.7554/eLife.97674.1)

This dataset includes raw data from the following data collected at the NIH/NIDCD:

Figure 5

Figure 9

Figure 9-S1

Figure 10

This dataset includes calcium imaging experiments that measure mechanosensitive calcium responses (in response to fluid flow) in zebrafish lateral-line hair bundles (L1-L4) in gpr156 mutants and sibling animals (Figure 5) at day 6. Specifically, this dataset shows that in the posterior lateral line, control responses to anterior flow are greater than posterior flow. In addition, gpr156 mutants have larger responses, similar to control responses to anterior flow.

This dataset also includes gpr156 mutants and sibling zebrafish microinjected to label single lateral line afferents with tdTomato, then immunostain...