WHAT PAX GENES DO IN THE KIDNEY

Of the nine known PAX genes, only two (PAX2 and PAX8) are expressed in the developing kidney. Genetic evidence in mice and humans indicates that PAX2 plays a critical role in normal renal development and may si t atop a molecular cascade which unfolds during the transition from un differentiated mesenchyme to the early stages of nephrogenesis. Less i s known about the role of PAX8 in kidney development; although PAXs is expressed in the S-shaped body and early proximal tubule, preliminary data suggest that renal morphogenesis is unaffected by its absence. I n this review, we discuss the basic aspects of PAX gene structure and function and how mutations of PAX2 might interfere with structure of t he developing nephron.