In situ hybridization analysis of SGPP1 mRNA in sections of nongravid and gravid uteri collected from unilaterally pregnant ewes on Days 20, 40, 80, and 120 of gestation. Corresponding bright field and dark field images of representative cross sections are shown. A section from Day 80 nongravid intercaruncular endometrium hybridized with radiolabeled sense cRNA probe served as a negative control. LE, endometrial luminal epithelium; GE, endometrial glandular epithelium; scSt, endometrial stratum compactum stroma; Tr, placental trophectoderm; PL, placental chorion; CAR, caruncular tissue; COT, cotyledonary tissue. Representative images are shown from independent samples (n = 4). Width of each field is 940 μm.