Model of Kif3a-mediated regulation of nephron number.

A Kif3a control is required in both ureteric and metanephric mesenchyme cells for processes that control nephron number. In ureteric cells Kif3a acts in a GLI3R-dependent manner to control expression of Wnt11/Ret and ureteric branching. In metanephric mesenchyme cells, Kif3a functions to control cell survival and expression of Fgf8, which is required for maturation of nephrogenic progenitors. The lineage-specific functions of Kif3a in ureteric and metanephric mesenchyme cells converge to control nephron number.