title: Transcriptomic sequencing of healthy human placenta: Sample CJM9
design: The subjects involved were part of the Rhode Island Child Health Study (RICHS), which enrolled a total of 899 mother/infant pairs at Woman and Infant’s Hospital of Rhode Island (Providence, RI, USA), from Sept 1, 2009 through July 31, 2014. All subjects provided written informed consent approved by the Institutional Review Boards at Women and Infants Hospital and Dartmouth College. For each subject and within 2 hours of delivery, samples of placenta parenchyma (totaling approximately 8–10 g of tissue) were excised. All samples were taken from the fetal side of the placenta, 2 cm from the umbilical cord insertion site, free of maternal decidua. RNA was collected from placenta using Qiagen RNeasy Mini Kit, and samples with a RNA Integrity Number above 5.0 were kept for sequencing (n = 19). Paired end libraries were prepared and sequenced on an Illumina HiSeq2000 at the University of Miami Miller School of Medicine Center for Genome Technology following their standard protocol. Across samples, an average of 42.3 million paired reads with an average quality of 34.5 were obtained. Sequences from each sample were aligned to the human genome (hg19) using TopHat2 default parameters, with an average of 27.1 million reads (~64% mapping rate) mapping successfully. 