Metabolism-associated genome-wide epigenetic changes in bovine oocytes during early lactation

Sci Rep. 2020 Feb 11;10(1):2345. doi: 10.1038/s41598-020-59410-8.

Abstract

Dietary intake in early lactating cows is outmatched by milk production. These cows experience a negative energy balance, resulting in a distinct blood metabolism and poor reproductive function due to impaired ovulation and increased embryo loss. We hypothesize that oocytes from lactating cows undergoing transient metabolic stress exhibit a different epigenetic profile crucial for developmental competence. To investigate this, we collected oocytes from metabolically-profiled cows at early- and mid-postpartum stages and characterized their epigenetic landscape compared with control heifers using whole-genome bisulfite sequencing. Early-postpartum cows were metabolically deficient with a significantly lower energy balance and significantly higher concentrations of non-esterified fatty acids and beta-hydroxybutyrate than mid-postpartum animals and control heifers. Accordingly, 32,990 early-postpartum-specific differentially methylated regions (DMRs) were found in genes involved in metabolic pathways, carbon metabolism, and fatty acid metabolism, likely descriptive of the epigenetic regulation of metabolism in early-postpartum oocytes. DMRs found overlapping CpG islands and exons of imprinted genes such as MEST and GNAS in early-postpartum oocytes suggest that early lactation metabolic stress may affect imprint acquisition, which could explain the embryo loss. This whole-genome approach introduces potential candidate genes governing the link between metabolic stress and the reproductive outcome of oocytes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cattle
  • CpG Islands
  • DNA Methylation*
  • Epigenesis, Genetic*
  • Female
  • Gene Expression Regulation*
  • Genome*
  • Lactation*
  • Metabolome*
  • Oocytes / cytology
  • Oocytes / metabolism*
  • Postpartum Period