Northern blot analysis of pig AKR1C1 mRNA expression in the ovary and uterus during the estrous cycle and pregnancy. A. Total RNA was isolated from ovaries on day 12 of the estrous cycle and pregnancy. B. Uteri were collected on days 12 and 15 of the estrous cycle, and on days 12, 15, and 30 of pregnancy. Blots shown are the results of a representative experiment; graphs show the average ± SEM of 3 independent experiments. C: estrous cycle; P: pregnancy.