Location: Livestock Issues Research
Title: Prenatal transportation stress alters genome-wide methylation of DNA in leukocytes from Brahman bull calvesAuthor
LITTLEJOHN, BRITTNI - Texas A&M Agrilife | |
PRICE, DEBBI - Texas A&M Agrilife | |
NEUENDORFF, DONALD - Texas A&M Agrilife | |
CARROLL, JEFFERY - Jeff Carroll | |
VANN, RHONDA - Mississippi Agricultural And Forestry Experiment Station (MAFES) | |
RIGGS, PENNY - Texas A&M Agrilife | |
RILEY, DAVID - Texas A&M Agrilife | |
LONG, CHARLES - Texas A&M Agrilife | |
WELSH, THOMAS - Texas A&M Agrilife | |
RANDEL, RONALD - Texas A&M Agrilife |
Submitted to: Plant and Animal Genome Conference
Publication Type: Abstract Only Publication Acceptance Date: 1/6/2020 Publication Date: 1/11/2020 Citation: Littlejohn, B.P., Price, D.M., Neuendorff, D.D., Carroll, J.A., Vann, R.C., Riggs, P.K., Riley, D.G., Long, C.R., Welsh, T.H., Randel, R.D. 2020. Prenatal transportation stress alters genome-wide methylation of DNA in leukocytes from Brahman bull calves. International Plant and Animal Genome Conference XXVIII, January 11-15, 2020, San Diego, CA. p. 109. Interpretive Summary: Technical Abstract: The role of the prenatal epigenome in shaping postnatal outcomes is largely unknown in the bovine species. We compared DNA methylation in leukocytes from prenatally stressed (PNS) relative to Control calves. Mature Brahman cows were transported (n = 48) for 2-h periods at 60, 80, 100, 120, and 140 (± 5) d of gestation or maintained as non-transported Controls (n = 48). Reduced representation bisulfite sequencing was used to assess differential methylation in leukocytes from a subset of 28-d-old bull calves (n = 7 PNS and 7 Control) born to Transported and Control dams. Samples from PNS calves contained 16,128 CG, 226 CHG, and 391 CHH sites that were differentially methylated relative to Control calves (C = cytosine; G = guanine; H = either adenine, thymine, or cytosine). Of the differentially methylated CG sites, 1,205 were located within promoter regions, 3,103 within introns, 1,260 within exons, and 10,560 within intergenic regions. Of those sites, 7,407 were hypermethylated (= 10% more methylated than Controls; P = 0.05) and 8,721 were hypomethylated (= 10% less methylated than Controls; P = 0.05). Because increased DNA methylation within gene promoter regions has been typically reported to suppress transcriptional activity, differentially methylated (difference = 10%; P = 0.05) CG sites located within promoter regions were used to predict alterations to biological pathways via pathway analysis (Ingenuity). In PNS calves, 113 pathways were identified as altered (P = 0.05). Among these were pathways related to behavior, stress response, and immune function. Furthermore, PNS calves from the entire population of calves born to Transported and Control dams exhibited more excitable temperaments, increased circulating concentrations of cortisol, and differential innate immune response to an endotoxin challenge. In support of our hypotheses, differential methylation of genomic DNA was detected in PNS calves, which was correlated with phenotypic differences observed in the larger population of calves in this study. Results suggest DNA methylation as a mechanistic basis for prenatal programming. Better understanding mechanisms by which prenatal programming alters the developmental trajectory of biological systems in utero presents novel opportunities to improve livestock phenotypes. |