Causative mutations in MommeD19 , MommeD27 , MommeD39 , MommeD42 , MommeD13 , MommeD33 and MommeD40 . (a) MommeD19 carries a mutation at a splice site of Smarcc1. Real-time RT-PCR and immunoblotting of embryos at 12.5 days post-coitum (dpc) showed reduced levels of Smarcc1 mRNA and Smarcc1 protein in heterozygotes (n ≥ 5 mice). Each track represents a different animal. Smarcc1 protein was detected at approximately 160 kDa. (b) MommeD27 harbors a mutation in a bromodomain of Pbrm1. Western blot analysis of 14.5 dpc embryo heads showed reduced levels of Pbrm1 in homozygotes. Each track represents a different animal. Pbrm1 was detected at approximately 190 kDa. (c) MommeD39 carries a mutation at a splice site of Smarca4. Real-time RT-PCR showed reduced Smarca4 mRNA in testes of heterozygotes (n ≥ 4 mice). cDNA sequencing revealed that the mutation in Smarca4MommeD39 results in use of an alternative splice donor site. (d) The mutation in MommeD42 introduces a premature stop codon at amino acid 411 of the Brd1 protein. (e) Mutations in MommeD13 and MommeD17 occur in the conserved SET domain of Setdb1. Real-time RT-PCR of Setdb1 mRNA from testes of heterozygotes and age-matched wild types (n = 4 mice). cDNA analysis revealed that the Setdb1MommeD13 allele is associated with the use of an alternative splice donor site in exon 20, leading to a 62 bp truncation. (f) MommeD33 carries a mutation at a splice site in Suv39h1. Western blot analysis of Suv39h1 in adult thymus showed reduced Suv39h1 in hemizygous mutant males. Each track represents a different animal. Suv39h1 protein was detected at 48 kDa. (g) The mutation in MommeD40 introduces a premature stop codon at amino acid 778 of Uhrf1. Western blot analysis of Uhrf1 revealed greatly reduced levels in 9.5 dpc embryos homozygous for the Uhrf1MommeD40 mutation. Each track represents a different animal. Uhrf1 protein was detected at approximately 90 kDa. Error bars indicate ± standard error of the mean. N.s., not significant. Asterisks indicate mutation.