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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
item QUAIL, LACEY - Texas Agrilife
item Miles, Jeremy
item PERRY, GEORGE - Texas Agrilife
item Cushman, Robert

Submitted to: Reproduction, Fertility and Development
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/30/2024
Publication Date: 12/6/2024
Citation: Kaps, M., Snider, A.P., Quail, L.K., Miles, J.R., Perry, G.A., Cushman, R.A. 2024. Transcriptomic analysis of luteal tissue supports the earlier onset of luteolysis in heifers with diminished ovarian reserve. Reproduction, Fertility and Development. 36. Article RD24130. https://doi.org/10.1071/RD24130.
DOI: https://doi.org/10.1071/RD24130

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 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 non-pregnant heifers with a low number of antral ovarian follicles (Open Low AFC) and hypothesized a reduced abundance of luteinizing hormone/choriogonadotropin receptor (LH/CG-R) and increased abundance of thrombospondin-1 (THBS1) 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. For 4 years, 10 heifers with the highest (High AFC) and 10 heifers with the lowest AFC (Low AFC) of the population (n = 120/year) were selected, synchronized and inseminated. On day 15 or 16 after insemination, reproductive tracts were collected, and pregnancy status was determined. Corpora lutea were isolated, weighed and underwent transcriptomic analysis. Key results. Transcript abundance of LH/CG-R was lower in Open Low AFC 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 onset 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.