Xenopus ILK (integrin-linked kinase) is required for morphogenetic movements during gastrulation

It has been suggested that ILK (integrin-linked kinase) participates in integrin- and growth factor-mediated signaling pathways and also functions as a scaffold protein at cell-extracellular matrix (ECM) adhesion sites. As the recently reported ILK knockout mice were found to die at the peri-implantation stage, the stage specific to mammals, little is known about the function of ILK in early developmental processes common to every vertebrate. To address this, we isolated a Xenopus ortholog of ILK (XeILK) and characterized its role in early Xenopus embryogenesis. XeILK was expressed constitutively and ubiquitously throughout the early embryogenesis. Depletion of XeILK with morpholino oligonucleotides (XeILK MO) caused severe defects in blastopore closure and axis elongation without affecting the mesodermal specification. Furthermore, XeILK MO was found to interfere with cell-cell and cell-ECM adhesions in dorsal marginal zone explants and to result in a significant loss of cell-ECM adhesions in activin-treated dissociated animal cap cells. These results thus indicate that XeILK plays an essential role in morphogenetic movements during gastrulation.