Global gene expression of the inner cell mass and trophectoderm of the human blastocyst

Abstract

Objective To investigate the global gene expression of inner cells mass and trophectoderm of the human primplantational blastocyst. Methods We used blastocysts which was 6 d after fertilization, and Gardner score 5AA. Microcapsules were used to separate the inner cells mass and trophectoderm. Single cell sequencing was performed. And the gene expression was analyzed by bioinformatics software. The unidentified hierarchical clustering analysis and Gene Ontology (GO) functional classification were used to analyze the differentially expressed genes. Results The 11 single cells from inner cells mass and 16 single cells from trophectoderm in 5AA preimplantational blastocysts were sequenced. We found there were 1 283 genes up-regulated in inner cell mass compared with trophectoderm. The GO biological function was mainly involved in DNA-dependent transcription resistance, signal transduction, cell differentiation, anti-apoptosis, nervous system development, cell adhesion, etc. These genes involved in MAPKs signaling pathway, actin cytoskeleton, adhesion,axis guidance, Jak-STAT, Wnt signaling pathway. We found there were 1 073 genes with up-regulated expression in trophectoderm compared with inner cell mass. Its GO biological function was mainly involved in transcription, DNA dependent transcription, cell cycle, protein catabolism, protein amino acid phosphorylation, protein transport, cell division, mitosis, ubiquitin-dependent protein decomposition, intracellular protein transport, etc. Those genes involved in ubiquitin-mediated proteolysis, sphingolipid metabolism, valine, leucine and isoleucine degradation, fructose and mannose metabolism, aminophosphonate metabolism, steroid biosynthesis, antigen processing and expression signal pathways. Conclusion The global gene expression of inner cells mass and trophectoderm of the human preimplantational blastocyst is revealed from the spatial dimension, indicating that they are coordinated with each other, and the process of embryo implantation are finely regulated. Further data analysis is expected to find the endogenous specific molecules for regulating embryo implantation. Key words: Blastocyst; Inner cells mass; Trophectoderm; Gene; Single cell sequencing