Partial loss of Ascl2 function affects all three layers of the mature placenta and causes intrauterine growth restriction

► The Del7AI deletion causes an imprinted intrauterine growth restriction phenotype. ► Expression of the imprinted gene Ascl2 is reduced in Del7AI maternal heterozygotes. ► Phlda2 expression is upregulated in Ascl2 hypomorphic placentae. ► Del7AI alters the three layers of the mature placenta. ► The mutant placentae lack trophoblast glycogen cells.