Genome-Wide Profiling and Differential Expression of mRNA and microRNA in Vitrified–Warmed Mouse Blastocyst

Blastocyst vitrification has significantly changed the embryo transfer method.Vitrification of human blastocysts may result in higher implantation success rates and heavier birth weightsin subsequent frozen embryo transfer cycles. This study investigated the effects of vitrification onthe transcriptome profiles and implantationof mouse blastocysts. First, a fold-change cutoff of±2 was used to distinguish differentially expressed genes. Transcriptomic analysis indicatedthat differentially expressed genes of vitrified–warmed blastocysts were mainly related to cell development, proliferation, projection,motility,and calcium-binding protein and MAPK-related signaling pathways.Second, we performed reverse transcriptase-quantitative polymerase chain reaction to verify the gene expression in the next-generation sequencing results, including increased genes such as GPR132, CDK6, FOS, and NFAT2and decreased genes such as DKK3 and MAPK10. Finally, blastocysts may communicate with the maternal uterine via microRNA to regulate gene expression in the embryo and endometrium. Prediction of microRNA candidateswas performed using the results of next-generation sequencing transcriptomicanalysis and validatedthroughmicroRNA assay. A total of 12 validated blastocyte microRNAs may affect uterine epithelial cell adhesion, trophectoderm development, invasive capacity, or immune responses to increase pregnancy success rates. In conclusion, vitrification alters the transcriptome of mouse blastocysts, resulting in small changes in gene expression and an increased implantation success rate. Embryos from B6CBF1 mice were cultured in human tubal fluidfor 3days. Embryo transfer was performed 2.5 days following mating. Six vitrified–warmed blastocysts were transferred to the right uterine horn in the same recipient. The same number of fresh blastocystswere transferred to the left uterine horn of pseudopregnant recipients. The mice were euthanized4days after embryo transfer.