Submitted to: Endocrine Journal
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/24/1999
Publication Date: 3/20/2000
Citation: Yamaguchi, H., Katsumura, M., Imakawa, K., Sakai, S., Christenson, R.K. 2000. Analysis of possible silencer elements of ovine interferon-tau gene. Endocrine Journal. 47(2):137-142. Interpretive Summary: Reproductive loss during early pregnancy is one of the most costly factors influencing the livestock industry. Such losses in sheep occur as a result of an impaired signal from the developing conceptus to the maternal system during implantation. In sheep, the gene controlling the conceptus signaling product (ovine interferon-tau; oIFNtau) is known. This study determined specific regions within the gene that control expression of the signaling product in an uterine cell culture system. Two regions between -700 to -654 and from -503 to -453 bases were found to be potential negative regulatory regions. Reduction of these silencer regions within the conceptus gene may improve maternal recognition of pregnancy and implantation. Improved implantation can increase embryo survival and improve lambing rates for the sheep industry.
Technical Abstract: To identify silencer elements of ovine interferon-tau (oIFNtau) gene, a variety of deletion constructs were prepared and examined for such regions by using transient transfection into human choriocarcinoma, JEG3, cells. Two regions between -700 to -654 and from -503 to -453 bases were found to be the potential negative regulatory regions. With probes prepared from those regions, gel mobility shift assay (GMSA) was then conducted. DNA-protein complexes were observed, but gel shift pattern was different between nuclear extracts from days 14 and 20 ovine trophectoderm; the latter exhibited strong and distinctive band patterns, which coincide with the reduction of oIFNtau production in vivo. Together, these observations suggest that the upstream sequences identified could serve as potential silencer regions for oIFNtau gene and that reduction in the transcription of the oIFNtau gene results from these silencer elements.