22-P010 The European Xenopus Resource Centre (EXRC)

Interestingly, little is known about their role in the AVE. The human ADTK1 homologue shares 92% identity with mouse. As for the Xenopus and chicken, there are two orthologs for each species. XADTK1 share, respectively, 60% and 42% identity with mADTK1. As for cADTK1, the orthologs share 37% and 28% identity. Besides its expression in the AVE, ADTK1 has a singular expression pattern during organogenesis. In situ hybridization reveals that this gene is present in the neural folds, secondary heart field and somites. In later stages, transcripts are present in the branchial arches, forebrain, midbrain, somites, rhombomeres and limbs. It is clear that all through mouse embryonic development ADTK1 is always absent from the presomitic region and heart tube. Preliminary data from work using the Xenopus and chick orthologs suggest that this gene may be involved in neural crest migration, neural tube closure and heart formation. Stem cells have the ability to renew themselves and can differentiate into a diverse range of specialized cell types; these are an important tool when studying the function of yet unknown genes. In order to evaluate ADTK1’s role during embryonic development, this gene has been genetically inactivated using the ES cell technology. Currently we are analysing its phenotype.