Figure S1. Haematoxylin and eosing stained endometrium from pregnant (A-C) and females in the estrous cycle (D-E).; Figure S2. Gene ontology analysis of significant differences between late estrous (ELG) and late pregnancy (LG).; Figure S3. Gene ontology analysis of significant differences between mid estrous (EMG) and non-pregnant samples (NP). from Endometrial recognition of pregnancy occurs in the grey short-tailed opossum (Monodelphis domestica)

Figure S1. In late pregnancy (A) and the equivalent time in the estrous cycle (D), the uterus becomes highly folded with few endometrial glands within these folds. In post-attachment pregnancy the endometrial glands are open, and glandular epithelial cells appear secretory in form (B), while in the equivalent stage of the estrous cycle, the glands are shrunken, compact, and glandular epithelial cells have shrunk in size (E). Towards the end of pregnancy the sub-epithelial stromal cell population is displaced and replaced by a network of sub-epithelial capillaries (C), however, in the estrous cycle, this epithelial cell population remains compact (F) which may prevent the formation of the sub-epithelial capillary network.; Figure S2.(A) Significantly over-represented gene ontology terms from the list of significantly down-regulated genes in estrous cycle (13 dpe) compared to non-reproductive uterus. (B) Significantly over-represented gene ontology terms from the list of significantly down-regulated genes in late gestation uterus compared to the estrous cycle.; Figure S3. (A) Significantly over-represented gene ontology in genes up-regulated in EMG compared to NR. (B) Significantly over-represented gene ontology in genes down-regulated in EMG compared to NR.