A murine homologue of the Drosophila brainiac gene shows homology to glycosyltransferases and is required for preimplantation development of the mouse

The neurogenic gene brainiac was first isolated in Drosophila melanogaster, where it interacts genetically with members of the Notch signaling cascade . We have isolated a murine homologue of the Drosophila brainiac gene and d elineated its highly specific expression pattern during development and adu lt life. We find particularly strong expression in the developing central n ervous system, in the developing retina, and in the adult hippocampus. Targ eted deletion of mouse Brainiac 1 expression leads to embryonic lethality p rior to implantation. Null embryos can be recovered as blastocysts but do n ot appear to implant, indicating that mouse Brainiac 1, likely a glycosyltr ansferase, is crucial for very early development of the mouse embryo.