Construction Protocol | Timed matings were undertaken, and noon on the date of the vaginal plug was taken to be E0.5. Embryos were subsequently harvested on the stipulated day. Germ cells (GFP-positive) and associated somatic cells (GFP-negative) were isolated separately from individual embryos using FACs sorting on the MoFLo XDP or FACS Aria platforms. Live cells, i.e. only those staining negative for propidium iodide, were collected, and typically purity checking on the GFP negative populations was >99%. RNA was isolated from FACs sorted purified cell populations using the Ambion PicoPure RNA isolation kit. Eluted RNA was used to obtain double-stranded-cDNA using the Clontech (SMARTER) Ultralow input RNA-Seq Kit according to the manufacturer’s protocol, or the Smart-Seq2 protocol. cDNA was normalized to 10ng in low-TE buffer and was sheared using Covaris S-series, and was cleaned up with Zymo DNA conc-5 and eluted in 12ul low TE. Libraries of ~300bp were generated 510 using Nugen Ovation® Ultralow DR (part No. 0330) with 15 PCR cycles. |