Fig. 7: Tip filaments depend on tip-localized myosins.
From: Myosin-dependent short actin filaments contribute to peripheral widening in developing stereocilia
a Representative images of His-TMOD1 stained row 1 stereocilia and row 2 stereocilia, co-labeled after expansion microscopy with antibodies to endogenous MYO3A or MYO15A (green) from P5 mice. NHS-ester (grey) stained total protein. The experiments were repeated three times with similar results. b His-TMOD1 (green, grey) labeling in Myo3 double mutant (Myo3aΔ14/Δ14 Myo3bΔ12/Δ12, noted in Supplementary Fig. 6a) and littermate control IHCs at P4. c Quantification of His-TMOD1 level from the tips of row 1 stereocilia in Myo3a;Myo3b G0 mutants generated via i-GONAD (Supplementary Fig. 6a) and in littermate control IHCs, each at P4. Sample size (stereocilia, cells, cochleae/mice): control (60, 12, 4), mutant (60, 12, 4). d HA-TMOD1 (green, grey) labeling in Myo15a mutant (Myo15aΔ25/Δ25) and littermate control (Myo15aΔ25/+) IHCs at P4. e Quantification of HA-TMOD1 level from the tips of row 1 stereocilia in Myo15a mutant and littermate control IHCs (P4). Sample size (stereocilia, cells, cochleae): control (125. 25, 6), mutant (85, 17, 5). In (c) and (e), normalized TMOD1 level from individual stereocilia were plotted as small dots with the color corresponding to their cochleae, represented as larger open circles. Results were plotted with mean ± SD based on cochleae. P values for two-tailed unpaired t tests are indicated. P < 0.05 is considered statistically significant. f His-TMOD1 (magenta, grey) labeling of an IHC 18 h after transfection with EGFP-K50R-MYO3A (green) and a neighboring untransfected cell (P5). F-actin was stained by phalloidin (blue). g Graphs of His-TMOD1 and EGFP-K50R-MYO3A level at row 1 or row 2 stereocilia tips. Simple linear regression analysis was applied and R-squared values were 0.52 (row 1) and 0.51 (row 2). h His-TMOD1 (magenta, grey) labeling of an IHC 18 h after transfection with EGFP-MYO15A-2 (green) and a neighboring untransfected cell (P5). i Graph of His-TMOD1 and EGFP-MYO15A-2 level at row 1 stereocilia tips. Simple linear regression analysis was applied and R-squared value was 0.88. Sample size (stereocilia, cochleae) in (g) and (i): MYO3A (245, 10), MYO15A (238, 9). Scale bars represent 5 μm. Source data are provided as a Source Data file.
