Altered mRNA Expression in Placental Tissues of Ewes Exposed to Ergot Alkaloids during Gestation.

Consuming ergot alkaloids found in endophyte-infected tall fescue [Lolium arundinaceum (Schreb.) Darbysh] seed causes intrauterine growth restriction due to uteroplacental insufficiency. The objective of this study was to assess the impact on gene expression levels in placental tissue from feeding ergot alkaloids during gestation. Thirty-six Suffolk ewes (78.24 kg ± 9.5) estimated to be carrying twins at d 35 of gestation were randomly assigned to one of two treatments: endophyte-free tall fescue seed (E-; 0.0 µg ergovaline + ergovalinine/g) or endophyte-infected tall fescue seed (E+; 4.14 µg ergovaline + ergovalinine/g) from d 35 – d 85 and d 86 – d 133 of gestation creating four unique dietary treatments: E-E-, E-E+, E+E-, and E+E+. Endophyte-infected tall fescue seed was fed at a level to provide 1772 µg of ergovaline + ergovalinine/hd/d for E+ treatments while an equal weight of endophyte-free seed (0.0 µg ergovaline + ergovalinine) was fed for E- treatments. Ewes were pair-fed across treatments in order to maintain equal DMI. Fetal and maternal necropsies were performed at d 133 of gestation. Placental samples were weighed, frozen in liquid nitrogen, and stored at -80°C. Total RNA was extracted from cotyledon placental tissue using TRIzol® and a PureLink® RNA Mini Kit (ThermoFisher Scientific). Total RNA was quantified and quality was assessed using an Agilent 2100 Bioanalyzer. RIN numbers of > 7 were considered sufficient quality. A subsample (n = 4) was selected for both the E+E+ and E-E- treatment groups and total cotyledon RNA was submitted for gene expression profiling via Illumina RNA-Seq (LC Sciences). Numerous genes were upregulated (P = < 0.01; n = 131) in E+E+ compared to E-E- and included genes involved in angiogenesis and vasoconstriction (FGA, APOH, HPX), hemostasis and coagulation (KNG1, FGA, PLG, FGB), oxidative reduction (PYROXD2, CYP2E1), cholesterol import and lipoprotein particles (APOC3, APOH, APOA2, GC, PON1), cell activation (FGA), and immune response (KNG1, AHSG). Several genes were down regulated (P < 0.01; n = 56) in E+E+ compared to E-E- and included genes involved in fatty acid metabolism, lipid oxidation, and beta-oxidation (ADIPOQ), G-protein coupled receptor (GPR151), signal transduction (HRH4), and cell proliferation (PODN). The consumption of ergot alkaloids during gestation directly effects the mRNA expression in cotyledon tissues.