Mutant selection

• Embryos are produced from homozygous-lethal and sub-viable knockout gene lines and checked for gross morphological abnormalities. Embryonic lethal lines are defined as those with no homozygous pups present at P14. Sub-viable lines are those with 0 < 13% of homozygous pups present at P14.
  • Mouse Phenotyping team at the Wellcome Trust Sanger Institute

Embryos are initially harvested at E14.5. If no embryos are present at this point, the line is harvested at E9.5.

E14.5 embryos undergo detailed phenotyping as part of the analysis pipeline. If no morphological abnormalities are identified, the line is harvested at E18.5 for further study.

Embryo analysis

• Embryos are imaged in 3D at E14.5 and E9.5 using High Resolution Episcopic Microscopy (HREM) at resolutions between 1 and 3 μ³.
  • Mohun Lab at the Francis Crick Insitute
• A pipeline is developed for micro-CT scanning of embryos at E18.5.
  • Schneider Group at the University of Oxford
• The placentas from knockout lines are imaged using histology, and annotated with placental phenotypes.
  • Hemberger Lab at the Babraham Institute
• Neural tissue in the brain and spinal cord of E18.5 embryos is examined using immunohistochemistry to gain further understanding of knockouts that cause perinatal death but do not result in morphological abnormalities at E14.5.
  • Houart Lab at King's College London
• The mRNA expression profile of knockout lines is studied, comparing mutant embryos with wild-types in order to derive molecular phenotypes.
  • Vertebrate Genetics and Genomics group at the Wellcome Trust Sanger Institute

Data review

• The HREM images of E14.5 embryos are studied by expert anatomists to identify tissue and organ abnormalities. The Mammalian Phenotype (MP) Ontology is used to associate each observed abnormality with a distinct phenotype term.
  • Weninger Lab at the Medical University of Vienna
• E9.5 mutant embryos are phenotyped according to the MP Ontology. Wild-type embryos are also phenotyped, in order to understand the range of morphological variations within ‘normal’ embryos.
  • Bhattacharya Group at the University of Oxford
• The cardiovascular system of E14.5 embryos are studied in detail, and provide additional phenotype information.
  • Cardiac Morphology Unit at UCL’s Institute of Cardiovascular Science and Institute of Child Health

Publication and data sharing

• The DMDD database and website is being continuously developed and enhanced to improve its functionality.
  • DMDD team in the Mohun Lab at the Francis Crick Insitute
• The e-Mouse Atlas Project provides an online database for normal mouse embryo anatomy and gene expression. The detailed and annotated images of mouse embryos are a valuable reference point for comparing with embryos from embryonic lethal lines. Work is in progress towards an equivalent reference atlas of placenta images from DMDD embryonic lethal lines.
  • Baldock Group at the Institute of Genetics and Molecular Medicine
• Gene line pages have reciprocal links with the IMPC (International Mouse Phenotyping Consortium) database in order to simplify the experience for users of embryonic lethal data.
• Phenotype data will also be available via the MGI database.
• Annotated images of phenotypes will additionally be available via PhenoImageShare.
• Transcriptomics data produced at the Sanger Institute is being published through Expression Atlas.