Moderate body weight loss and one-carbon metabolite supplementation in early gestation beef heifers alters the fetal Longissimus dorsi transcriptome

Authors: SWANSON, REBECCA - South Dakota State University; KING, LAYLA - University Of Minnesota Crookston; DINIZ, WELLISON - Auburn University; HAUXWELL, KATHLYN - North Dakota State University; HURLBERT, JENNIFER - North Dakota State University; ENTZIE, YSSI - North Dakota State University; SYRING, JESSICA - North Dakota State University; WARD, ALISON - University Of Saskatchewan; DAHLEN, CARL - North Dakota State University; REYNOLDS, LAWRENCE - North Dakota State University; Crouse, Matthew; CATON, JOEL - North Dakota State University

Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 4/23/2025
Publication Date: 10/4/2025
Citation: Swanson, R.M., King, L.E., Diniz, W.J., Hauxwell, K.M., Hurlbert, J.L., Entzie, Y.L., Syring, J.G., Ward, A.K., Dahlen, C.R., Reynolds, L.P., Crouse, M.S., Caton, J.S. 2025. Moderate body weight loss and one-carbon metabolite supplementation in early gestation beef heifers alters the fetal Longissimus dorsi transcriptome [abstract]. Journal of Animal Science. 103(Supplement 3):151. https://doi.org/10.1093/jas/skaf300.183.
DOI: https://doi.org/10.1093/jas/skaf300.183

Interpretive Summary:

Technical Abstract: Moderate body weight (BW) loss occurs naturally throughout production cycles and is detrimental to fetal growth and development. Supplementing one-carbon metabolites may alleviate improper fetal development. The objective of this study was to determine the effects of early gestation nutrient restriction and one-carbon metabolite (OCM) supplementation on fetal skeletal muscle gene expression. Angus-cross heifers (n = 72) were subjected to estrus synchronization and bred to a single sire using female-sexed semen. At breeding, heifers were stratified by BW in a 2 × 2 factorial: fed to gain 0.45 kg/d (CON) or lose 0.23 kg/d (RES) BW and to receive corn carrier with OCM supplement (+OCM) or without (-OCM) from d 0 to 63 of gestation. The OCM supplement consisted of vitamin B12 (20 mg/wk) and folate (320 mg/wk) injections and dietary rumen-protected methionine (7.4 g/d) and choline (44.4 g/d). Pregnancy was determined and fetal sex confirmed on d 35 of gestation using transrectal ultrasonography, resulting in 31 pregnant heifers across treatments. On d 63 of gestation, heifers were slaughtered and the uterus was excised for fetal dissection. Fetal Longissimus dorsi (LD) tissue was collected into RNAlater and stored at -8 degrees. Total RNA was extracted and after quality control, sequenced on the Illumina NovaSeq 6000 platform. After quality control, reads were mapped to the ARS-UCD1.2 reference genome using STAR. Differential gene expression was analyzed using DESeq2 (log2FC >/= |1| and P /= 2 and FDR /= 4-fold in RES+OCM. There were 62 DEG in RES+OCM vs. CON+OCM, and 63 DEG in RES+OCM vs. RES-OCM. Interestingly, the Tyrosine metabolism pathway was enriched in both the RES+OCM vs. CON+OCM and RES+OCM vs. RES-OCM contrasts, and cytosolic DNA-sensing pathways was enriched in the RES+OCM vs. RES-OCM comparison. Tyrosine metabolism has essential roles in catecholamine and thyroid hormone synthesis. No other pathways were enriched among the remaining contrasts. There were 61 DEG in RES-OCM vs. CON+OCM. There were 121 genes in RES-OCM vs. CON-OCM. MATN1 and EPYC were downregulated > 4-fold in RES-OCM. There were 92 DEG in CON-OCM vs. CON+OCM. HSPA6 is involved in the cellular response to heat stress and was upregulated more than 2-fold in CON-OCM. Our results suggest that moderate BW loss and one-carbon metabolite supplementation affect the fetal LD transcriptome. In fact, pathway analysis suggests supplementation of one-carbon metabolites in moderate BW loss heifers during early gestation affects gene expression in pathways associated with fetal growth and development, and biological function.