XLOC-040580, a Novel lncRNA, Modulates Porcine Zygote Activation Progress

Background: Long noncoding RNAs (lncRNAs) play an important role in porcine preimplantation embryonic development, but the regulatory mechanism of lncRNAs during zygote activation (ZGA) remains unclear.Methods: We analyzed the transcriptome data of porcine fetal fibroblasts (PEF), porcine induced pluripotent stem cells (piPSCs) and embryos at different developmental stages before implantation, and found that lncRNAs specifically expressed at ZGA stage including XLOC-040580, and further predicted its target genes TPRA1 and BCL2L1. XLOC-040580 was knocked down by microinjection and the expression of ZGA related genes was detected by qRT-PCR. Microinjection of siRNA corresponding to target genes at the 1-cells, the blastocyst development rate was counted, and single cell sequencing was performed to analyze the regulatory network of target genes and its related mechanisms.Results: By analyzing the transcriptome data of porcine preimplantation embryos, we found that XLOC-040580 was specifically expressed during zygote activation. Knockdown of XLOC-040580 resulted in decreased blastocyst development rate, total blastocyst cell number and TE cell number. XLOC-040580 target genes TPRA1 and BCL2L1 are also specifically expressed in ZGA stage. The knockdown of XLOC-040580 target genes also blocked porcine embryonic development and affected the gene expression of ZGA-related pathways such as cell cycle, histone modification and trophoblast formation during porcine embryonic development.Conclusion: We found and confirmed that lncRNA XLOC-040580 played a key role in the ZGA process, and its target genes (TPRA1, BCL2L1) also coordinated early embryonic development.