A comprehensive set of transcriptome landscapes of human pre-implantation embryos and embryonic stem cells have been explored using single-cell RNA-Seq technique, which has been published on Nature Structural & Molecular Biology this month. This work was finished through a collaboration of Dr. Jie Qiao’ group from Third hospital of Peking University, and the Dr. Fuchou Tang and Dr. Ruiqiang Li’s group from BIOPIC, College of Life Sciences. It was supported by National Basic Research Program of and National Natural Science Foundation of China.
 

 

Deciphering the temporal and spatial patterns of gene expression in human embryos is a crucial step toward understanding the molecular mechanism regulating human early embryonic development. Because of technical difficulties as well as scarcity of human samples, the mechanisms of human early embryonic development are still largely unknown and the dynamics of global gene expression during the process of hESC derivation have not been documented. In this study, the authors provided the first comprehensive gene expression profiling of the human preimplantation embryos and through hESC derivation at single-cell and single-base resolution, and identified more than two thousand novel lncRNAs in human embryos. They have also analyzed the gene expression characteristics of human late blastocysts and separated them into three lineages- trophectoderm (TE), epiblast (EPI) and primitive endoderm (PE). Furthermore, this study has demonstrated the earliest gene expression changes when deriving hESCs from EPI of blastocysts.

 

In the end, the authors compared their method with an alternative commercialized single-cell RNA-Seq method, SMART-Seq. They found that the approach used in this study recovered more expressed genes, had better coverage for 5’ ends of the cDNAs, and showed better technical reproducibility than Smart-Seq.

 

This is an important study that applies global gene expression analyses to individual cells of early human embryos and human embryonic stem cells. The results pave the way for dissecting the molecular regulation of early human embryonic development and provide insight into pluripotency and the molecular identity of hESCs.