Dominant negative expression of a cytoplasmically deleted mutant of XB/U-cadherin disturbs mesoderm migration during gastrulation in Xenopus laevis

摘要: XB/U-cadherin is a maternal Xenopus cadherin which mediates interblastomere adhesion in early embryogenesis. In order to explore its role gastrulation, we expressed cytoplasmic deletion mutant of (XBΔc38) under the control CMV promoter embryos. This truncated XB-cadherin fails form complexes with catenins and does not mediate cell-cell aggregation as shown by transfection mouse Ltk− cells. Injections for into dorsal-marginal region four cell stage embryos resulted dominant negative expression after MBT. Two different phenotypes were observed dose dependent manner: high doses (125–250 pg DNA) led severe distortions gastrulation movement. Involution mesoderm was impaired, posterior migrated laterally around blastopore formed two bands axial tissue. Low (up 50 posteriorized phenotype disorganized neural structures. Both could be rescued coinjection cDNA constructs containing wild-type XB/U-cadherin. encoding protein both extracellular domains yielded normal phenotypes. These results suggest that proper function essential movements during gastrulation.