Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 4/23/1999
Publication Date: N/A
Technical Abstract: The glucocorticoid cortisol is present within porcine fetuses or their uterine environment throughout gestation. If cortisol is to influence fetal development, then GR must be present. The current study was conducted to determine the presence of fetal GR mRNA in fetal liver and placentae and to examine effects of breed and uterine environment. Porcine efetuses were obtained on days (d) 24, 30, and 40 of gestation from each of 3 treatments: intact (INT), unilaterally hysterectomized-ovariectomized white crossbred (UHO), and intact Meishan (ME) gilts (n = 5-6/treatment/ day). A 436-bp cDNA was produced using reverse transcription and polymerase chain reaction procedures with pig liver total RNA and primers complementary to porcine GR. The cDNA was cloned into a PCR II vector and sequenced. Northern hybridization analyses were conducted using 30 ug of total RNA. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA expression was measured to adjust for lane loading differences. Relative concentrations of GR mRNA were reported as arbitrary units after analysis of covariance using GAPDH as a covariate. Embryonic liver steady state GR mRNA expression did not vary among treatments but was highest (P < 0.01) on d 24 (15402 +/- 849 vs 12150 +/- 737 vs 12246 +/- 777; d 24, d 30, and d 40, respectively). Placental GR mRNA was lower (P = 0.03) in UHO fetuses on d 24 (14540 +/- 1027) compared with INT fetuses (17646 +/- 1149). ME placental GR mRNA increased (P < 0.01) between d 30 (13393 +/- 1158) and d 40 (18703 +/- 1141) and on d 40 was greater (P = 0.02) in ME than in white crossbred fetuses (14843 +/- 1477). These data indicate the presence of GR mRNA in porcine fetal tissues during early gestation and provide strong evidence for an involvement of cortisol in porcine fetal development.