The C-terminal region of KIF26B is indispensable for nephron progenitor condensation and kidney formation in mice.

Loss of Kif26b function causes renal agenesis or hypoplasia in mice, and a KIF26B mutation resulting in deletion of the C-terminal region has been identified in a human patient with a congenital kidney disorder. However, the role of this region during kidney development is unclear; thus, to investigate this, we generated mice lacking the C-terminal region of KIF26B (Kif26b-C) using CRISPR/Cas9. Homozygous Kif26b-C mice showed bilateral renal agenesis, resembling Kif26b knockout mice. Histological analysis revealed loss of the nephrogenic zone and impaired nephron progenitor condensation at embryonic day 18.5. In situ hybridization showed reduced Gdnf in the metanephric mesenchyme and reduced Wnt11 in ureteric buds, indicating disruption of the Gdnf-Wnt11 signaling loop. These findings suggest a key role for the KIF26B C-terminal region in kidney morphogenesis.