Transcriptomic analysis of the chorioallantois in equine premature placental separation.

The transcripts from equine chorioallantois of thirty-three premature placental separation and four control were compared. Placental tissues were collected either at the farm (n=13) or from placentas submitted to the University of Kentucky Veterinary Diagnostic Laboratory (UKVDL) (n=24). The villous CA tissues were collected immediately adjacent to the cervical star at a site with grossly apparent chorionic villi. Samples from this site were preserved in RNAlater® for RNA sequencing. Total RNA was isolated from tissue samples using RNeasy Mini Kit (#74104: Qiagen). RNA concentrations and quantities were confirmed using the Nanodrop 2000 spectrophotometer (ThermoFisher Scientific, MA, USA). Then, RNA integrity was assessed using the Bioanalyzer 2100 system (Agilent Technologies, CA, USA). All samples had a 260/280 ratio >2.0 and RNA integrity number (RIN) >7.0.