Figure 3: Anatomy and key molecules of the transduction apparatus. (a) Electron microscopy image of two adjacent stereocilia in a hair bundle. The two stereocilia are joined by a tip link. (b) Relevant structures in the region of the tip link. Abbreviations: Lower tip-link density (LTLD), upper tip-link density (UTLD) (c) Key molecules in the region of the tip link. Abbreviations: Myo1C (myosin 1c), CDH23 (cadherin 23), PCDH15 (protocadherin 15), MYO15A (myosin 15a) (Fig. (a) image courtesy of R.A. Jacobs and A.J. Hudspeth, reprinted from Gillespie & Müller [17] with permission from Elsevier, figures (b) and (c) modified after Gillespie & Müller [17].