In Situ hybridization analysis of receptor activator of NFKB ( TNFRSF11A ). Protected transcripts in endometrium from days 0, 5, 7.5, 10, 12, 13, 15 and 17 of the estrous cycle and days 10, 12, 13, 15 and 17 of pregnancy were visualized by liquid emulsion autoradiography and imaged under bright-field and dark-field illumination. While expression was low in all tissues evaluated, evidence of TNFRSF11A expression is detected in the LE on day 12 of the estrous cycle and pregnancy. A representative day 12 pregnant section was hybridized with radiolabeled sense cRNA probe (sense) to serve as a negative control. All other images are representative from four biological replications. 4× objective and 10× eyepiece for original magnification 40×.