In Situ hybridization analysis of PGR mRNA expression in porcine endometrium. 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. Note the greatest expression is during (day 0) and after estrus (day 5) abundant in the luminal epithelium (LE) and glandular epithelium (GE) and stromal (ST) cell types. PGR expression is greatly reduced in the LE and GE by day 10 and nearly devoid on day 12 of the estrous cycle and pregnancy, although still present in ST cells. A representative day 5 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×.