Our latest data release includes HREM image data for an additional 5 lines, and HREM phenotyping data for 4 lines. Five additional early lethal lines have also been identified, as well as placental phenotype data for more than 100 mutant lines, with associated placenta morphology and yolk sac images.
Throughout the DMDD project we continue to add data for existing lines, and in this release we have added P14 viability for mutant lines, Theiler stage (where assessed), and the voxel size of each HREM image stack.
Initial analysis of the new HREM phenotyping data shows two lines newly associated with heart defects.
Oaz1 ASSOCIATED WITH DORV
Oaz1 is a gene regulating levels of polyamines within the cell and is widely distributed in cells and tissues of the body. Our data now shows that removal of this gene causes a serious abnormality in heart development in which the vessel normally carrying blood from the left ventricle of the heart (the aorta) is in fact attached to the right ventricle (a defect known as “double outlet right ventricle” or DORV). As with many mutant lines, the embryos also show extensive swelling of the body (“edema”).

Cc2d2a ASSOCIATED WITH VSD AND OSTIUM PRIMUM DEFECT
Cc2d2a encodes a protein that plays a critical role in formation of cell cilia and mutations in this gene are associated with diseases such as Meckel syndrome type 6, which results in a broad range of symptoms such as polydactyly, cleft palate and kidney malformations. Our data reveals that removal of the Cc2d2a gene also has profound effects on heart development. Not only do the embryo hearts fail to complete separation of the left and right ventricular chambers (a “ventricular septal defect”), they also fail to form a proper wall between the left and right atrial chambers (an “ostium primum defect”). In addition, they have lost a swath of tissue at the junction between the atria and ventricles (the “vestibular spine”) that is essential for completing chamber separation.

Many of the genes studied by DMDD do not currently appear to be associated with any disease, however careful analysis of the phenotypes from lines such as these could contribute to the identification of new disease models, and our data is freely available at dmdd.org.uk in order to encourage this. For more information please email contact@dmdd.org.uk.