Localization of CCN4 and CCN6 mRNA by in situ hybridization in the endometrium during the estrous cycle and pregnancy in pigs. Representative uterine sections from Day 30 and 15 of pregnancy stained with sense RNA probes are shown as negative controls for CCN4 and CCN6, respectively. Tissue sections from the kidney and small intestine are shown as positive controls for CCN4 and CCN6 mRNA, respectively. D, Day; C, estrous cycle; P, pregnancy; LE, luminal epithelium; GE, glandular epithelium; CE, chorionic epithelium; St, stroma. Bars = 100 µm.