Variance of conceptus interferon tau (IFNT), produced by the embryonic trophectoderm, is known as a major conceptus protein that signals the process of maternal recognition of pregnancy in ruminants, essential for the maintenance of early pregnancy. Similar to other IFN genes such as IFNA and IFNB, multiple IFNT genes are present. However, some kinds of IFNT genes actively transcribed and regulated in bovine conceptuses have not been well characterized. In this study, during the course of bovine IFNT gene transcription through the use of next generation sequencer SOLiD3, revealed that among 38 IFN genes registered, only two transcripts, IFNT1 and IFNTc1, were found in conceptuses during early pregnancy. Also, to identify a transcription factor(s) involved in the regulation of IFNT genes, mRNAs for various known transcription factors were investigated by real-time PCR in conceptus tissues, respectively. Furthermore, compared to the IFNT genes, IFNT1 and IFNTc1 had same active levels, which were previously shown to correlate with the appearance of effective antiviral activity. However, the expression levels of these Luc activities differed. Bovine ear fibroblast (EF) cells were cotransfected with luciferase reporter constructs carrying upstream (–631 to -51) promoter regions of IFNT1 or IFNTc1 and various transcription factor expression plasmids, CDX2, AP1(JUN), ETS2 and/or cAMP-response element binding protein (CREB)-binding protein (CREBBP). CDX2, either alone with the other 2 transcription factors, was found to increase luciferase activity approximately 14- and 11-folds, respectively. The degree of transcriptional activation of the IFNTc1 gene was not similar to that IFNT1 gene by AP1, ETS2 or/and CREBBP, expression plasmid. These results suggest that two isoforms of bovine conceptus IFNT genes are regulated differently in conceptuses during early pregnancy.

Interferon tau (IFNT), produced by the mononuclear trophectoderm, signals the process of maternal recognition of pregnancy in ruminants, but its expression in vivo is not well characterized. Objectives of this study were to determine IFNT gene isoforms expressed in the bovine uterus, and to identify differences in promoter sequences of IFNT genes that differ in their expression. Through the RNA-seq analysis of bovine conceptuses on days 17, 20 and 22 (day 0 = day of estrus), the expression of only two IFNT transcripts, IFNT1 and IFNTc1, were found, which were indeed classified into the IFNT gene clade. IFNT mRNAs were highest on day 17, and then decreased on days 20, and 22, which were also supported by the results of quantitative RT-PCR. Bovine ear-derived fibroblast (EF) cells were then cotransfected with luciferase reporter constructs carrying 5‘-upstream (positions -1000 to +51) regions of IFNT1 or IFNTc1 and various transcription factor expression plasmids. CDX2, either alone or with other Ap-1, ETS2 and/or CREBBP transcription factors, was found to increase luciferase activity approximately 10 and 18 fold more than twice of those cotransfected with bIFNT1, c1-Luc construct. Furthermore, The degree of transcriptional activation by a combination of the AP1, ETS2, CREBBP and/or CDX2 expression vectors was similar to that of CDX2 along plasmid. However, expression patterns of these Luc activity differented. Whereas bIFNTc1-Luc showed lowest antivity had than bIFNT1-Luc reports. Although, lowest antivity had of the bIFNTc1 –Luc report, cotransfected with the bIFNTc1-Luc construct and AP1(JUN) or/and ETS2 expression plasmid, Luc activity was enhanced approximately 2 and 4-fold more than the bIFNT1-Luc. Furthermore, along CDX2 expression factor had high effect on activity of bIFNT1-Luc reporter than the c1 gene in EF cells. These results suggest that two forms of IFNT genes are expressed in utero and their transcriptional regulations differ.