Ypel1: a novel nuclear protein that induces an epitheliallike morphology in fibroblasts

Background: Embryonic development depends on the regulation of cell morphol ogy and behaviour to carry out morphogenesis. One example of this is the de velopment of the face, which is constructed from independent blocks of tiss ue that must grow in a coordinated way and then fuse to form a continuous t issue. Results: We have isolated a novel gene of unknown function from mouse and q uail embryos in a search for genes involved in craniofacial development. Se quence analysis of this gene, known as Ypel1, demonstrates a striking level of amino acid conservation between vertebrates and invertebrates but no si gnificant homology with any other characterized genes. Ypel1 is expressed i n the ventral half of early embryos including the branchial arches from whi ch the face derives. Ypel1 localizes to the nucleus, and transfection into fibroblasts induces an epithelial-like transition, which is accompanied by alterations to the cytoskeleton and cell adhesion machinery. In addition, h uman YPEL1 localizes to chromosome 22q11.2, a region associated with a numb er of syndromes involving malformation of the craniofacial complex. Conclusion: These data suggest a role in regulation of cellular morphology and behaviour that is important for development of the craniofacial complex .