Testing the effect of endocrine-disrupting chemicals (EDs) on imprint erasure. (A) Experimental design. JF1 females (tail up) were mated with OG2 males (tail down). Pregnant dams (G0) were treated with EDs or oil control from 8.5 dpc to 12.5 dpc. Imprint erasure occurs during this time in PGCs of the exposed G1 embryos. One orange star = exposed G0 generation; two orange stars = exposed G1 embryo. (B) GFP positive male and female germ cells and somatic cells were collected from the gonads by FACS sorting. (C) Results of RNA Sequenom allelotyping experiments of imprinted transcripts are displayed for cells treated with an ED or control vehicle (‘oil’); letters in parentheses indicate separate SNPs. Average (n = 3) allele-specific transcription is shown in color, 100% paternal (blue) to 100% maternal (red), with 50% biallelic in yellow. Many imprinted genes have parental allele-specific transcription in PGCs at 9.5 dpc but biallelic transcription in FGCs and MGCs (but not in FSCs and MSCs) at 13.5 dpc. Statistically significant (P <0.05) aberrations in erased allele-specific transcription, greater than 5% or 10%, are marked by thin or bold white rectangles, respectively.