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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 #417718
Research Project: Applying Nutritional Strategies to Improve Early Embryonic Development and Progeny Performance in Beef Cows

Location: Livestock Bio-Systems

Title: Transcriptomic analysis of luteal tissue supports the earlier onset of luteolysis in heifers with diminished ovarian reserve

Author
item KAPS, M - University Of Veterinary Medicine
item Snider, Alexandria - Alex
item QUAIL, LACEY - Texas Agrilife
item PERRY, GEORGE - Texas Agrilife
item Miles, Jeremy
item Cushman, Robert - Bob

Submitted to: Reproduction, Fertility and Development
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/30/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Pregnancy losses cost cow calf producers nine billion dollars annually. Eighty percent of pregnancy losses occur because the embryo and uterus fail to communicate properly during the second week of pregnancy. We investigated the ovarian mechanisms controlling production of progesterone, the hormone responsible for maintaining pregnancy, in fertile and sub-fertile heifers. Sub-fertile heifers lacked the key physiological pathways to produce progesterone at the proper concentrations to maintain pregnancy during this critical window. Options for cow calf producers are to provide interventions that improve progesterone concentrations in this window and possibly propagate sub-fertility or to identify sub-fertile heifers and remove them from the breeding herd.

Technical Abstract: Context. Antral follicle count (AFC) is reflective of ovarian reserve and linked to reproductive performance in mammalian females. We previously demonstrated an earlier upregulation of endometrial oxytocin receptor transcription in heifers with low AFC, indicating an earlier onset of luteolysis. Aims. We aimed to support the earlier onset of luteolysis in Open Low AFC heifers. We hypothesized a reduced abundance of luteinizing hormone/choriogonadotropin receptor (LH/CG-R) and increased thrombospondin-1 (THBS1) abundance in luteal tissue of those heifers. We further investigated if classical interferon stimulated genes (ISGs) are already upregulated in response to conceptus-derived interferon tau. Methods. After determination of AFC, the top 10% (High AFC) and the bottom 10% (Low AFC) of the population distribution were selected, synchronized and inseminated. On day 15 or 16 after insemination, reproductive tracts were collected, and pregnancy status defined by presence or absence of a conceptus. Corpora lutea were isolated, weighed and underwent transcriptomic analysis. Key results. Transcript abundance of LH/CG-R was lower in Low AFC Open heifers compared to all other subgroups. Transcript abundance of THBS1 was upregulated in Open vs. Pregnant heifers and showed greater abundance in Low vs. High AFC heifers. Luteal weights and abundance of ISGs did not differ between heifers of differing AFC groups or pregnancy status. Conclusions. The patterns of luteal LH/CG-R and THBS1 abundance support the concept of earlier induction of luteolysis in Open heifers with diminished AFC. Implications. This may result in a shorter window for maternal recognition of pregnancy and contribute to inferior reproductive performance.