Alternative splicing signatures in preimplantation embryo development.

Background: Preimplantation embryo development is a highly ordered sequence of processes and it requires a precise temporal and spatial control of gene expression. Alternative splicing (AS) is a crucial process that changes the genomic instructions into functional proteins, playing a critical role in the regulation of gene expression. Therefore, studies of AS can significantly improve our understanding of transcription and splicing events in preimplantation embryo development. Results: To study signatures of AS in embryo development, we firstly identified the critical stage for gene transcription during the preimplantation embryo development. By analyzing single cells RNA-seq (scRNA-seq) data, we found that the two-cell stage is a critical stage for gene transcription in preimplantation embryo development. Further study showed that AS was widespread in preimplantation embryo development, especially at the two-cell stage. In combination with high-throughput chromosome conformation (Hi-C) data, we demonstrated that AS genes were highly enriched in TAD boundaries, while they had no relationship with the A/B compartment and TAD. Conclusion: Our results provide new insight into the relationship among AS, gene transcription and chromatin structure in preimplantation embryo development.