An ENU recessive mutagenesis screen identifies a lethal mutation Abca12.

Mutagenised 129/Sv males were crossed with C57BL/6 females and the resultant G₁ males crossed again to C57BL/6. Pedigrees were established by crossing G₁ males with their G₂ daughters and the G₃ offspring were then subjected to genome wide screening for absence of homozygosity of the mutagenised (129/Sv) strain (A). The recessive embryo lethal 12 (el12) mutation was identified using this approach and mapped by recombination to Chromosome 1 (B). Open rectangles indicate haplotypes homozygous for the 129/Sv mutagenised background and filled rectangles are C57BL6/J homozygotes or heterozygotes. Recombination frequency and markers position are indicated. A missense G1997D mutation was identified in Abca12 (C, D). The el12 mutation alters a residue in the second TM region of the protein which is conserved in all species examined (human, mouse, dog, chicken, platypus, microbat and shrew) (E).