Description
In humans, the embryonic genome activation (EGA) program is functional by day 3 after fertilization. The 6-8 cell stage embryo (day 3 post-fertilization) starts the process of compaction that leads to the generation of the tightly organized cell mass of the morula and is followed by differentiation of the morula into a blastocyst. The transition from day 3 embryos to day 5 blastocysts is likely to be controlled by many and specific changes in the expression of different genes. We used mRNA amplification technique and compared the transcriptomes of day 3 human embryos and trophectoderm (TE) cells from day 5 human blastocysts to identify transcripts that are differentially expressed during the embryo-to-TE transition and involved in the TE specification.