Whole genome bisulfite sequencing of bovine morula derived from metabolically divergent dairy cows

Lactating cows experience transient metabolic stresses during postpartum which results in abnormal concentrations of non-esterified fatty acids and beta-hydroxybutyrate that can affect embryo-maternal communication and ultimately reproductive success. We hypothesize that metabolic challenges in lactating cows influence DNA methylation changes of the embryos prior to implantation affecting genes involved in embryo developmental competency. Therefore, we compared whole genome bisulfite sequencing (wgbs) of morulas derived from in vitro produced 2-4 cell embryos and transferred in the oviduct of metabolically profiled lactating cows until day 7. Similar stage of in vitro production (IVP) embryos were transferred to the oviduct of nulliparous heifers as a metabolically unchallenged control. Bisulfite-Seq DNA libraries were generated from groups of five morulas using an EZ DNA methylation-direct kit and Pico-Methyl seq library preparation kit (Zymo Research), and parallel sequenced using the illumine HiSeq2500 system at the institute of Genome Biology, Leibniz-Institute for Farm Animal Biology (FBN), Dummerstorf, Germany.