Progesterone and interferon tau regulated genes in the endometrium of the ovine uterus and expression of interferon stimulated genes in the corpus luteum during early pregnancy in sheep



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Texas A&M University


During early pregnancy in ruminants, progesterone (P4) from the corpus luteum (CL) and interferon tau (IFNT) from the conceptus act on the endometrium to regulate genes including interferon stimulated genes (ISGs) that are hypothesized to be important for uterine receptivity and conceptus growth. Previous custom ovine cDNA array analyses identified candidate genes that were regulated by pregnancy, P4 and/or IFNT in the ovine uterus. The first study validated pregnancy, P4 and/or IFNT regulated genes identified by previous custom ovine cDNA microarray analyses. ACTA2, COL3A1, POSTN, SPARC, S100A2, STAT5A and TAGLN were examined. POSTN was upregulated by P4 and S100A2 was downregulated by IFNT. Moreover, functional studies showed that POSTN stimulated attachment of ovine trophectoderm cells. However, neither COL3A1, SPARC, ACTA2 nor TAGLN was regulated by pregnancy, P4 or IFNT in the ovine endometrium. Collectively, these results confirmed that POSTN and S100A2 are P4 and IFNT regulated, respectively, and likely involved in uterine receptivity to conceptus implantation during early pregnancy. The second study determined expression of ISGs in the CL of pregnant ewes. MX1, MX2, ISG15, OAS1, and RSAD2 mRNAs were increased on Day 14 of pregnancy and maintained to Day 18, indicating that IFNT induced expression of ISGs in the CL. These results confirmed that locally produced IFNT has paracrine effects and also endocrine effects on reproductive organs other than the uterine endometrium and maternal immune system.