Early pregnancy diagnose by expression of interferon-tau stimulated genes in peripheral blood immune cells in beef cattle

Abstract

The maternal recognition of pregnancy between days 15 and 19 post-ovulation is involved in one of the main biological challenges to reach high fertility rates in cattle. Interferon-tau (IFN-tau) secretion by the early conceptus is crucial on corpus luteum maintenance and establishment of pregnancy and stimulates a greater abundance of specific genes on peripheral immune cells in dairy cattle and sheep. However, the effect of embryo presence on the expression of interferon-stimulated genes (ISG) in beef cows is not known yet. Therefore, this study aimed: (1) evaluate the abundance of transcripts of ISGs on peripheral blood mononuclear immune cells during early pregnancy in Bos Indicus beef cattle; and (2) determinate the viability and accuracy of detection of pregnant and non-pregnant cows by expression of ISG between 12 to 20 days post artificial insemination (AI). To reach these objectives, Nelore cows will have the estrous cycle manipulated by hormonal treatments and their ovulations synchronized for timed-AI. Progesterone concentrations, an abundance of transcripts of ISGs on peripheral blood immune cells, and size and luteal blood flow will be measured between days 15 and 30 post-AI. As result, is expected that early molecular marks will be found to identify the pregnancy status in Bos Indicus beef cattle. (AU)