No abstract

Interferon-tau (IFN-τ) is a pregnancy recognition signal secreted from the trophectoderm cells of the bovine conceptus that induces the expression of IFN-stimulated genes (ISG) in immune cells. The expression of ISG in peripheral blood leukocytes has been suggested as a potential tool for early pregnancy diagnosis. IFN-τ induces an increase in abundance of several ISG in peripheral mononuclear leukocytes between 18 and 20 days after fixed-time AI. We evaluated the abundance of 2 genes (ISG15 and LGALS3BP) stimulated by the conceptus using samples collected from 4 cell types: peripheral blood mononuclear cells (PBMC), total blood leukocytes, cervical cells, and total milk leukocytes, and we compared these four methods as pregnancy predictors on day 20 after timed AI in dairy cattle.