AN ANCIENT CONSERVED GENE EXPRESSED IN THE HUMAN INNER-EAR - IDENTIFICATION, EXPRESSION ANALYSIS, AND CHROMOSOMAL MAPPING OF HUMAN AND MOUSE ANTIQUITIN (ATQ1)

We constructed and screened a human fetal cochlear cDNA library to ide ntify genes involved in hearing and deafness. From this library we iso lated a cDNA corresponding to the highly conserved ancient gene antiqu itin (ATQ1). The plant homolog of ATQ1 is thought to be involved in re gulating turgor pressure, a function that also would be essential for cells of the mammalian cochlea. Northern blots of 13 human fetal tissu es show antiquitin to be highly expressed in cochlea, ovary, eye, hear t, and kidney. Using RT-PCR of rat cochlear hair cell-specific cDNA li braries, we detect antiquitin expression in outer hair cells, but not in inner or vestibular type 1 hair cells, suggesting that antiquitin i s not expressed ubiquitously in the cochlea. Human ATQ1 was mapped to human chromosome region 5q31 using fluorescence in situ hybridization, and mouse ATQ1 was mapped to mouse chromosome 18 by single-strand con formation polymorphism mapping of interspecific backcross progeny DNAs . Four human antiquitin-like sequences, possibly pseudogenes, were als o identified and mapped. (C) 1997 Academic Press.