a) TEM analysis of hECCs (NCCIT) with heavy metal staining, arrow indicates VLPs. Boxed region is shown with higher magnification in an inset. Scale bar = 500 nm. Shown is a representative example of two independent experiments.
b) TEM immuno-gold labeling of hECC (NCCIT) with Gag/Capsid antibodies. Shown is a representative example from 2 independent experiments.
c) Secondary only control for Immuno-gold labeling of human blastocysts. Shown is a representative example from 8 fields of view.
d) Model figure summarizing HERV-K transcriptional regulation in human embryos and in vitro cultured pluripotent cells. Dashed lines indicate inference of OCT4, DNA methylation and HERV-K level changes at implantation from those observed between naïve and primed hESCs, in the absence of data from actual postimplantation human embryos.