Tissue- and development-dependent expression of the small GTPase Arf6 in mice.

The small GTPase Arf6 is a member of the Arf (ADP-ribosylation factor) family. Although the function of Arf6 has been heavily studied at the cellular level, its physiological function at the whole animal level is largely unknown. In this study, we examined both the tissue distribution and developmental timing of Arf6 expression in wild type mice to obtain valuable information to speculate on the physiological function of Arf6. Western blot analysis using anti-Arf6 antibody revealed that Arf6 was ubiquitously expressed with its developmental timing differing in a tissue-specific manner. These results were supported by Arf6 mRNA in situ hybridization experiments, which showed that Arf6 was highly expressed in the polarized epithelial cells and embryonic mesenchymal cells of most tissues in a temporally dependent manner. Taken in toto, our results suggest that the expression of Arf6 in mouse tissues is precisely regulated in a development- and tissue-dependent manner.