Submitted to: Domestic Animal Endocrinology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 6, 2002
Publication Date: November 1, 2002
Citation: KIM, J.G., VALLET, J.L., ROHRER, G.A., CHRISTENSON, R.K. CHARACTERIZATION OF PORCINE UTERINE ESTROGEN SULFOTRANSFERASE. DOMESTIC ANIMAL ENDOCRINOLOGY. 2002. v. 23(4). p. 493-506. Interpretive Summary: Uterine capacity contributes to litter size in swine. Previous genome mapping revealed a region on porcine chromosome 8 associated with uterine capacity. Comparison of porcine and human genetic maps suggests that the porcine estrogen sulfotransferase gene may be located in this region. Estrogen sulfotransferase is an enzyme that catalyzes the addition of sulfate to estrone and estradiol, which makes them water soluble and inactive. This reaction may play a major role in the control of estrogen levels in endometrium. The objective of this study was to 1) obtain full length estrogen sulfotransferase cDNA, 2) examine estrogen sulfotransferase mRNA expression from porcine endometrium, and 3) map the estrogen sulfotransferase gene. Using reverse transcription-polymerase chain reaction and by screening of an expressed sequence tag library, we obtained full-length estrogen sulfotransferase cDNA. Expression of estrogen sulfotransferase mRNA was elevated in the endometrium of White composite gilts from day 15 to day 20 of pregnancy, remained elevated on day 30, and decreased significantly from day 30 to 40. Estrogen sulfotransferase may play a role in modulating the effect of estrogen on the endometrium or other tissues during early pregnancy in the pig. The estrogen sulfotransferase gene was mapped to 65 cM on chromosome 8 near the region, which was known to be associated with uterine capacity. These novel findings may provide insight into the function of estrogen sulfotransferase during pregnancy in pigs and support our hypothesis that the estrogen sulfotransferase gene may affect uterine capacity.
Technical Abstract: Uterine capacity contributes to litter size in swine. Previous gene mapping analyses revealed a quantitative trait locus (QTL) for uterine capacity located on chromosome 8. Comparison of porcine and human genetic maps suggests that the estrogen sulfotransferase (STE) gene may be located near this region. The objectives of this study were to 1) clone the full length cDNA for STE, 2) determine the STE gene expression during early pregnancy, and 3) map the STE gene. Using reverse transcription-polymerase chain reaction (RT-PCR) and iterative screening of an expressed sequence tag (EST) library, we obtained the full coding region of the STE cDNA, consisting of 1886 bp. Expression of STE mRNA in the endometrium of White composite gilts (n = 3 to 4 each) was determined by Northern blotting using 30 ug of total RNA from endometrium of Day 10, 13, and 15 cyclic, and Day 10, 13, 15, 20, 30, and 40 pregnant gilts. STE mRNA expression was elevated in the endometrium of Days 20 and 30 pregnant gilts (P < 0.01) than other days of pregnancy. These findings show that STE mRNA expression in the endometrium is temporally regulated during early pregnancy, and this pattern of gene expression may be important for endometrial function during early conceptus development. Using a microsatellite subcloned from a STE containing BAC genomic clone, the STE gene was mapped to 65 cM on chromosome 8, in the same region as the uterine capacity QTL.