Differential Gene Regulation of the Human Blastocyst Trophectoderm and Inner Cell Mass by Progesterone

Knowledge of action of progesterone (P4) on the human preimplantation embryo is lacking. The objective of this study was to determine expression of a mitochondrial P4 receptor (PR-M) in the trophectoderm (TE) and the inner cell mass (ICM) of the human blastocyst and to determine P4-induced gene expression during growth from the cleavage to the blastocyst stage. Previously cryopreserved cleavage stage embryos were treated with P4 (10−6 M) or vehicle until blastocyst development. Cells from the TE and the ICM of dissected euploid embryos underwent RNA-seq analysis, while other embryos were used for analysis of nuclear PR (nPR) and PR-M expression.