title: Regression of the corpus luteum in the presence of an embryo in a heifer at 18 days after breeding.
mesh_terms: D000818:Animals; D001947:Breeding; D002417:Cattle; D003338:Corpus Luteum / Q000166:cytology*; D004622:Embryo, Mammalian; D004721:Endoplasmic Reticulum; D005260:Female; D006652:Histological Techniques; D008055:Lipids / Q000032:analysis; D008854:Microscopy, Electron; D008928:Mitochondria; D011247:Pregnancy; D011374:Progesterone / Q000097:blood; D013194:Staining and Labeling
chemical_list: D008055:Lipids; D011374:Progesterone