Comprehensive analysis of Ephrin ligand and receptor expression reveals exclusive domains during nephrogenesis for...

Interactions between ephrins and their Eph receptors regulate a broad range of cellular processes, including attraction, repulsion, adhesion and migration, all of which play crucial roles in tissue remodeling and homeostasis. While several ephrin ligands and Eph receptors are known to be expressed in the developing kidney, their specific roles, particularly during nephrogenesis, remain poorly understood. The development of the Xenopus pronephros provides an accessible and relatively simple model for studying vertebrate nephrogenesis. Through a comprehensive gene expression analysis of all ephrin ligands and Eph receptors present in Xenopus genomes, we have identified members of the Eph-ephrin signaling pathway that may contribute to pronephric development. Among them, efna3, which encodes an ephrin ligand, is strongly expressed in the ventral region of the pronephric anlage and later in the intermediate and distal segments of the developing tubule. This expression pattern is strikingly complementary to that of epha4 and epha7, which are expressed in the region forming the proximal tubule. This suggests a potential role for efna3-epha4/epha7 signaling in establishing a boundary between these domains during pronephros development.