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ARS Home » Plains Area » Clay Center, Nebraska » U.S. Meat Animal Research Center » Livestock Bio-Systems » Research » Publications at this Location » Publication #146519
Title: ANALYSES OF OVINE INTERFERON-TAU GENE TRANSCRIPTION USING FEEDER CELL FREE-CAPRINE TROPHOBLAST CELL LINE, HTS-1

Author
item MATSUDA, FUKO - UNIV TOKYO, JAPAN
item XU, NING-CHUN - UNIV TOKYO, JAPAN
item Christenson, Ronald
item SAKAI, SENKITI - UNIV TOKYO, JAPAN
item IMAKAWA, KAZUHIKO - UNIV TOKYO, JAPAN

Submitted to: Biology of Reproduction Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 3/14/2003
Publication Date: 6/1/2003
Citation: MATSUDA, F., XU, N., CHRISTENSON, R.K., SAKAI, S., IMAKAWA, K. ANALYSES OF OVINE INTERFERON-TAU GENE TRANSCRIPTION USING FEEDER CELL FREE-CAPRINE TROPHOBLAST CELL LINE, HTS-1. BIOLOGY OF REPRODUCTION ABSTRACTS. 2003. v. 68(Suppl. 1). p. 274-275. Abstract No. 395.

Interpretive Summary:

Technical Abstract: Interferon-tau (IFNtau) is a protein secreted from embryonic trophectoderm of the ruminant ungulates during peri-implantation period. This protein is considered essential for the process of maternal recognition of pregnancy. There are more than 10 ovine IFNtau genes so far identified, on the genes, oIFNtauo10, appears to be expressed predominantly and only minute amounts of mRNA were found for the other, oIFNtauo8. Because a placental cell from ruminants was not available, human choriocarcinoma JAR and JEG3 cells had been used for analyses of transcription regulation of IFNtau genes. Recently, a trophoblast cell line derived from caprine placenta, termed HTS-1, was established. With the use of two cell types and genes with different degrees of transcription in utero, cell specific expression of IFNtau genes could be studied. To elucidate molecular mechanisms by which cell specific expression of IFNtau genes are regulated, the 5'-upstream regions from -654 to 51 (+1=cap site) base of oIFNtauo10 and oIFNtauo8 genes were inserted to luciferase reporter plasmids and were evaluated for their transcriptional activity using transient transfection analyses. Such constructs with wild-type, deleted or mutated upstream regions of oIFNtauo10 or oIFNtauo8 genes were evaluated in JEG3 and HTS-1 cells. The promoter region containing Ets-2 site rather than the enhancer region with AP-1 and GATA sites appeared to be essential for IFNtau gene transcription in HTS-1 cells. This finding was confirmed with co-transfection of AP-1 and/or Ets-2 expression plasmids in which over-expression of Ets-2 alone or in combination with AP-1 exhibited higher degree of transcriptional activity. Nuclear proteins extracted from JEG3, HTS-1 and ovine conceptuses possessed different amounts of AP-1 and Ets-2 proteins, HTS-1 had least amounts of Ets-2. Electrophoretic mobility shift assay confirmed that nuclear proteins from JEG3 and HTS-1 cells specifically bound to the Ets-2 site of oIFNtauo10. The specific binding was also detected in the oIFNtauo8 promoter region, but the binding protein did not appear to be Ets-2. These results indicated that caprine trophoblast HTS-1 cells support transactivation of oIFNtauo10 and oIFNtauo8 reporter constructs, and Ets-2 binding to the promoter region appears to be a key element in the regulation of cell specific expression of oIFNtau genes.