RNA-sequencing of placenta during the second half of gestation in sows

Cholestasis of pregnancy endangers fetal and neonatal survival, however, the underlying mechanisms are largely undetermined. By RNA-sequencing analysis of developing placentas, we identified "bile acids secretion" and "complement and coagulation system" as the most affected KEGG pathway during late pregnancy. In "bile acids secretion" pathway, the downregulated placental carbonic anhydrase II (CA2) expression may in part account for the impaired placental bile acids transport in response to maternal cholestasis. In "complement and coagulation system", the activated placental C5a receptor 1(C5aR1) might provide further evidence for the potential correlation of serum C5a concentration and fetal death as previously observed in humans. Collectively, these results provide new explanation for impaired placental bile acids transport as pregnancy advances, and imply the potential role of "complement and coagulation system" activation in causing adverse fetal outcomes. We perform RNA-seq on sow's placenta at day 60 of gestaion (G60), day 90 of gestaion (G90) and farrowing day (L0).RNA-seq was completed on an Illumina HiSeq 2000, paired-end 100bp reads.