- 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.
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.
- Embryos are imaged in 3D at E14.5 and E9.5 using High Resolution Episcopic Microscopy (HREM) at resolutions between 1 and 3 μ3.
- A pipeline is developed for micro-CT scanning of embryos at E18.5.
- The placentas from knockout lines are imaged using histology, and annotated with placental phenotypes.
- 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.
- The mRNA expression profile of knockout lines is studied, comparing mutant embryos with wild-types in order to derive molecular phenotypes.
- 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.
- 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.
- The cardiovascular system of E14.5 embryos are studied in detail, and provide additional phenotype information.
Publication and data sharing
- The DMDD database and website is being continuously developed and enhanced to improve its functionality.
- 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.
- 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.