Ampd3 (AMP deaminase 3) was maternally expressed in E13.5 placenta but biallelic in E13.5 embryo (Schulz
R et al, 2006).
However, Okae H et al, (2012) provided
strong evidence of negligible expression of Ampd3 by qPCR and whole transcriptome sequencing in E
13.5 placentas. They suggest that this gene is not imprinted. This is concordant with Proudhon and Bourc'his, (2010) caution that maternal contamination of placental tissues may
cause apparent imprinted maternal expression.