Contains image and phenotype data for embryonic lethal knockout mice. DMDD is database allowing to search by gene, phenotype or tissue type. The data sheds new light on genes that are critical for embryo development and survival. High-resolution 3D image analysis and tissue histology are used to identify abnormalities in both embryos and placentas from embryonic lethal lines. It provides Full-resolution images, phenotypes annotated on the relevant images and Phenotype penetrance data for each line. The database also includes gene expression profiles for embryos from knockout lines.