Transfer of cellular material between the uterine epithelium and trophoblast during the early stages of implantation.
D000818:Animals; D010064:Embryo Implantation / Q000502:physiology*; D004717:Endometrium / Q000166:cytology / Q000502:physiology*; D004848:Epithelium; D005260:Female; D051379:Mice; D008854:Microscopy, Electron; D010063:Ovum / Q000166:cytology; D011247:Pregnancy; D014327:Trophoblasts / Q000166:cytology / Q000502:physiology*