Journal: bioRxiv
Article Title: Single-Cell Profiling of the Developing Organ of Corti Identifies Etv4/5/1 as Key Regulators of Pillar Cell Identity
doi: 10.64898/2026.01.19.700450
Figure Lengend Snippet: a. At E18, PROX1 + -IPCs, OPCs and DCs are arranged in ordered rows in the basal region of the control cochlea. In the less mature apical region (lower panel) the lateral rows of DCs are not completely aligned yet. In contrast, in an Etv Triple KO cochlea overall cellular alignment is disrupted in both the basal and apical regions. a’. In a control cochlea, OPCs (CD44 + , magenta) form a single ordered row in the basal region but are only weakly CD44 + in the apex. In an Etv Triple KO cochlea multiple rows of CD44 + -OPCs are present in the basal and apical regions. b. Cross-sectional Z-stacks of the OC from the basal region of a control and an Etv Triple KO. In the control, the single CD44 + /PROX1 + -OPC (arrow) is located adjacent to the first OHC (numbered). In the Etv Triple KO, three OPCs (arrows), are intermixed with the first two rows of OHCs (numbered). c. The positions of the six nearest PROX1 + -nuclei were mapped relative to fourth row PROX1 + -cells (see text for details). The radar plot illustrates results for control and Etv Triple KOs. In control OCs, the spatial alignment of PROX1 + -DCs is regular (green profile). In contrast, in Etv Triple KOs spatial patterning is disrupted (magenta). d . Surface view of the OC in control and Etv Triple KOs at E18 labeled with anti-S100A1, a marker of IHCs, PCs, and DCs, and phalloidin. In controls, DCs (arrows) form dumbbell shapes between OHCs. Although there are some patterning defects in the Etv Triple KO OC (arrows), overall expression of S100A1 appears comparable to control. S100A1-labeling of IHCs was also present in Etv Triple KOs (not shown). e. Surface views of an E18 control OC illustrating all HCs (magenta) and OHCs (POU4F3 + (magenta) and BCL11B + (green)) and a similar view from an Etv Triple KO showing an over-production of HCs in the lateral region of the OC(numbered), many of which are negative for BCL11B (arrows). f-f’’. Cross-sectional Z-stack views of the OC from a control and an Etv Triple KO at E18. In the control, a single IHC (arrow), three OHCs (numbered), a single IPC and OPC, and three DCs are present. In an Etv Triple KO, an ectopic PROX1 + -HC (asterisk) is present in the pillar cell region. g-g’’. Cross-sectional Z-stack views as in g but labeled with MYO6 instead of POU4F3. In the Etv Triple KO, a PROX1 + /MYO6 + -cell is present in the PC region of the OC (arrowhead and asterisk). Inset: Image of the ectopic hair cell (asterisk) in gray scale with increased contrast for improved detection of MYO6 labeling. h. Surface views of the basal region of the OC from animals with the indicated genotypes at E16. In controls a single row of NGFR + -IPCs (magenta) is already present. Some IPCs are also positive for NPY (green). In contrast, in an Etv4/5/1 Triple KO only minimal expression of NGFR is present while NPY expression is absent. In addition, ectopic HCs (arrows) are present in the pillar cell space. i. Surface view of the basal region of the OC from control and an Etv Triple KO at E16. In the control a single row of MYO6 + -IHCs and three rows of MYO6 + /BCL11B + -OHCs are present. In an Etv Triple KO only three rows of OHCs are present by comparison with the four rows present in some regions at E18 . Some PROX1 + -nuclei are present in the HC nuclear layer (arrows) but are negative for HC markers. Scale bar in a,b,e,f,g (same in h), and j (same in i), 20 μm.
Article Snippet: The primary antibodies used were rabbit anti-MYOSIN6 (Proteus Biosciences 25-6791, RRID:AB_10013626 at 1:500 dilution), rabbit anti-NPY (Peninsula Laboratories T-4070, RRID: AB_518504 at 1:500 dilution), goat anti-NGFR (R&D Systems AF367, RRID:AB_2152638 at 1:500 dilution), goat anti-PROX1 (R&D Systems AF2727, RRID:AB_2170716 at 1:500 dilution), goat anti-SOX2 (R&D Systems AF2018, RRID:AB_355110 at 1:500 dilution), rat anti-CD44 (BD biosciences 550538, RRID: AB_393732 at 1:500 dilution), mouse anti-POU4F3 (Santa Cruz biotechnology, RRID: AB_2167543 at 1:200 dilution), goat anti-MYOSIN6 (Kelley lab custom made at 1:500 dilution), mouse anti-CTIP2 (BCL11B) (Abcam ab18465, RRID: AB_2064130 at 1:500 dilution), rabbit anti-NRP2 (Cell Signaling D39A5, AB_2155250 at 1:500), sheep anti-S100A1 (R&D Systems, AF4476, AB_2183326 at 1:500).
Techniques: Control, Labeling, Marker, Expressing, Comparison