Regulator of neurite outgrowth required for normal hearing and vision. In the embryo, expressed in otic cyst, lateral trunk epidermis and underlying mesodermal tissue, limb bud, maxillary process, cochlea, retina, tongue, tooth primordium, central nervous system, and primordia of visceral organs including lung, gastrointestinal tract and pancreas. In the central nervous system, expressed primarily in dorsal thalamus, cerebellum and medulla. During inner ear development, detected early in the otic vesicle, and later in cochlear and vestibular sensory epithelia. Present in the presumptive organ of Corti by 14.5 dpc, and then confined to the supporting cell types at later stages of embryonic development and at the newborn. In the vestibular sensory epithelia, present at the lumenal surface. However, it is detected in the non-hair cell region, presumably in the lumenal processes of the supporting cells. Transiently expressed in the spiral and vestibular ganglion neurons (at protein level) (PubMed:19936227). First expressed at 8.5 dpc. In the newborn, broadly detected in neural retina. Later, in P10 retina, expression is enhanced in the inner nuclear and outer plexiform layers. Expression in retina decreases as development proceeded, and is detected in the inner nuclear layer and in a subset of cells in the ganglion cell layer of adults (PubMed:23543054). Male and female mice grow without showing any external abnormalities and are fertile but display auditory deficits. In the developing inner ear, mice show pronounced reduction of cochlear innervation, despite normal gross morphology and general organization of the organ of Corti (PubMed:19936227). Adult mice have reduced startle response and impaired auditory brainstem responses consistent with mid-frequency range hearing loss (PubMed:21298075). Retinas in postnatal development display a delay in synaptogenesis (PubMed:23543054). Belongs to the SLITRK family.