The mammalian inner ear is an exquisitely sensitive instrument, unrivaled in its cellular specialization and differentiation. It consists of the older vestibular system, essential for the maintenance of balance and spatial orientation, and the newer auditory system, that converts sound waves to electrical signals which are sent to the brain. For a quick refresher course on this topic click on the various symbols on the painting on the index. Understanding of cochlear and vestibular macro-and micromechanics depends on the physical, bioelectrical, and biochemical properties of constituent tissues, and pervading and surrounding fluids of the inner ear. It is the macromolecules and their interactions that endow a tissue with its specific properties.
Functional specialization is achieved through macromolecular specialization.
Although cellular metabolism reflects the integrated activity of several thousand gene products, functional diversity is conferred by relatively few. We have chosen this approach rather than the more rapid identification of multiple tissue-specific genes through, for instance, subtractive screening of cDNA libraries. The latter suffers from the shortcomings that plague all fishing expeditions, i.e. low selectivity and variable efficiency. Having identified the putative candidate genes, their biological significance remains to be established. Furthermore, there is no guarantee that the most valuable genes made it into the net.