Developmental equivalence of epiblast stem cells (EpiSCs)

Epiblast stem cells (EpiSCs) were derived from the epiblast or the ectoderm (epi/ect) of pre-gastrula stage to late-bud stage mouse embryos. To identify if the EpiSCs retain any original stage specific characteristics or which developmental stage of epi/ect they most closely related to, we performed microarray analysis to compare the gene expression profile of multiple EpiSC lines with that of epi/ect of 7 different stages. Eighteen EpiSC lines established from R1-129 embryos of different stages and 1 line (EpiSC9) imported were harvested in triplicate cultured separately for 3 days. The * marks the subline thawed at a different time and harvested but originated from the same embryo. EpiSC9_T is an RNA sample provided by Dr Tesar. ESCs, iPSCs and MEFs were prepared accordingly. For the epiblast samples, in order to avoid the averaging effect by pooling samples, we linearly amplified the RNA starting from a single epiblast or ectoderm.