REVIEW ARTICLE: Control of Interferon‐Tau Expression During Early Pregnancy in Ruminants

PROBLEM: A type I interferon (IFN), termed IFN-tau (tau), is responsible for the establishment and maintenance of early pregnancy in cattle and sheep. The control of IFNtau gene (IFNT) expression is not completely understood. METHOD OF STUDY: This article will provide an overview of recent progress made in understanding the dynamic expression pattern of IFNT during pre- and peri-attachment conceptus development. RESULTS: Several ubiquitous transcriptional regulators (Ets2 and AP1) and at least two trophectoderm factors (Cdx2 and Dlx3) control IFNT transcription during early pregnancy. Co-activators (CBP/p300) are also involved in this process. At least two uterine-derived factors (GM-CSF and FGF2) stimulate IFN-tau production in bovine trophectoderm, and multiple signaling pathways are functionally linked with IFNT expression. CONCLUSION: Although understanding the regulation of IFNT expression is far from complete, considerable progress has been made in uncovering how uterine-derived factors and key placental-specific transcriptional regulators control IFNT expression.