Collection of term placental samples: Placenta tissue was collected at term at the
University of Arkansas for Medical Sciences following informed consent from
mothers. The protocol was approved by the Institutional Review Board at UAMS
(NCT01104454). Included in this study were non-smoking mothers without gestational
diabetes, pre-eclampsia or other complications who had either vaginal or
cesarean deliveries (Table 1).
Preparation, sequencing, and data analysis of RNA-seq libraries: Total RNA was
isolated from 20 placenta (pooled from 6 separate locations) using RNeasy columns
[5] including DNase digestion. cDNA libraries were prepared using NebNext reagents
as previously described [5]. Single-read 36-bp sequencing was performed using a
GAIIX (Illumina). RNA-seq data for other tissues (liver, skeletal muscle, adipose,
kidney, lung breast, and heart) were acquired in FASTQ format from the Illumina
BodyMap 2.0 project. Alignment to the human genome (hg19) was carried out using
Bowtie [6]. All data were analyzed in Avadis-NGS and SeqMonk software packages.