Jun-Xue Jin

Zygotic genome activation (ZGA) is a pivotal event during early mammalian embryonic development and is regulated by multiple molecular factors. In mice, previous studies have demonstrated that long non-coding RNAs (lncRNAs) and transposable elements (TEs) participate in the regulation of this process. However, the functional roles of TEs-associated lncRNAs in porcine ZGA remain largely unknown. In this study, we identified a previously unannotated lncRNA associated with a SINE transposable element sequence in porcine parthenogenetically activated embryos, which we named LincSAKP. LincSAKP exhibited peak expression at the 8-cell stage, coinciding with ZGA, was predominantly localized in the nucleus, and lacked protein-coding potential. Functional analyses demonstrated that depletion of LincSAKP resulted in developmental arrest at the 8-cell stage, accompanied by reduced chromatin accessibility, impaired nascent transcription, and aberrant expression of multiple ZGA marker genes and transcription factors. Transcriptomic analysis combined with rescue experiments identified EP300 as a critical downstream target of LincSAKP. Notably, Depletion of either LincSAKP or EP300 impairs histone H3K27ac modification. EP300 overexpression effectively alleviated the developmental defects caused by LincSAKP depletion. Collectively, our findings identify EP300 as a downstream mediator of LincSAKP in regulating zygotic genome activation, providing insights into the functional network of SINE-associated lncRNAs during parthenogenetically activated early embryonic development. This study expands our understanding of the functional roles of TE-associated non-coding RNAs in early embryonic development and provides a potential theoretical basis for improving the efficiency of in vitro culture of porcine embryos.

Tyrosine sulfation is a widespread posttranslational modification in mammals and is known to influence protein function and signaling. However, its functio

The zygotic genome activation (ZGA) is crucial for the development of pre-implantation embryos. Long noncoding RNAs (lncRNAs) play significant roles in many biological processes, but the study on their role in the early embryonic development of pigs is limited. In this study, we identify lncFKBPL as an enhancer-type lncRNA essential for pig embryo development. lncFKBPL is expressed from the 4-cell stage to the morula stage in pig embryos, and interference with lncFKBPL leads to a developmental arrest at the 8-cell stage. Mechanistic investigations uncover that lncFKBPL is able to bind to MED8, thereby mediating enhancer activity and regulating FKBPL expression. Additionally, FKBPL interacts with the molecular chaperone protein HSP90AA1, stabilizing CDK9 and boosting its protein-level expression. Elevated CDK9 levels enhance Pol II phosphorylation, facilitating ZGA. Our findings illuminate the role of lncFKBPL as an enhancer lncRNA in pig ZGA regulation and early embryo development, providing a foundation for further exploration in this area.

Melatonin supplementation during in vitro maturation (IVM) improves porcine oocyte maturation and embryonic development by exerting antioxidative effects. Nevertheless, the mechanism by which melatonin prevents polyspermy after in vitro fertilization (IVF) remains unclear. Here, we examined the effects of melatonin on cytoplasmic maturation and the incidence of polyspermic penetration in porcine oocytes. No statistically significant difference was observed in the rate of first polar body formation between the groups (Control, Melatonin, Melatonin + Luzindole, and Melatonin + 4-P-PDOT). Interestingly, melatonin supplementation significantly improved the cytoplasmic maturation of porcine oocytes by enhancing the normal distribution of organelles (Golgi apparatus, endoplasmic reticulum and mitochondria) and upregulating organelle-related gene expressions (P < 0.05). However, these promotional effects were counteracted by melatonin antagonists, suggesting that melatonin enhances cytoplasmic maturation through its receptors in porcine oocytes. Melatonin supplementation also significantly improved the rate of diploid and blastocyst formation after IVF by promoting the normal distribution of cortical granules (P < 0.05). In conclusion, melatonin supplementation during in vitro maturation of porcine oocyte improves fertilization efficiency and embryonic developmental competence by enhancing cytoplasmic maturation.

The multi-gene editing porcine cell model can analyze the genetic mechanisms of multiple genes, which is beneficial for accelerating genetic breeding. However, there has been a lack of an effective strategy to simultaneously perform precise multi-gene editing in porcine cells. In this study, we aimed to improve the efficiency of CRISPR RNP-mediated precise gene editing in porcine cells. CRISPR RNP, including Cas9 protein, sgRNA, and ssODN, was used to generate precise nucleotide substitutions by homology-directed repair (HDR) in porcine fetal fibroblasts (PFFs). These components were introduced into PFFs via electroporation, followed by PCR for each target site. To enhance HDR efficacy, small-molecule M3814 and phosphorothioate-modified ssODN were employed. All target DNA samples were sequenced and analyzed, and the efficiencies of different combinations of the CRISPR RNP system in target sites were compared. The results showed that when 2 μM M3814, a small molecule which inhibits NHEJ-mediated repair by blocking DNA-PKs activity, was used, there was no toxicity to PFFs. The CRISPR RNP-mediated HDR efficiency increased 3.62-fold. The combination of CRISPR RNP with 2 μM M3814 and PS-ssODNs achieved an HDR-mediated precision gene modification efficiency of approximately 42.81% in mutated cells, a 6.38-fold increase compared to the control group. Then, we used the optimized CRISPR RNP system to perform simultaneous editing of two and three loci at the INS and RLN3 genes. The results showed that the CRISPR RNP system could simultaneously edit two and three loci. The efficiency of simultaneous editing of two loci was not significantly different from that of single-gene editing compared to the efficiency of single-locus editing. The efficiency of simultaneous precise editing of INS, RLN3 exon 1, and RLN3 exon 2 was 0.29%, 0.24%, and 1.05%, respectively. This study demonstrated that a 2 μM M3814 combination with PS-ssODNs improves the efficacy of CRISPR RNP-mediated precise gene editing and allows for precise editing of up to three genes simultaneously in porcine cells.

In mice, retrotransposon‐associated long noncoding RNAs (lncRNA) play important regulatory roles in pre‐implantation development; however, it is largely unknown whether they function in the pre‐implantation development in pigs. The current study aims to screen for retrotransposon‐associated lncRNA in porcine early embryos and identifies a porcine 8‐cell embryo‐specific SINE‐associated nuclear long noncoding RNA named SAWPA. SAWPA is essential for porcine embryonic development as depletion of SAWPA results in a developmental arrest at the 8‐cell stage, accompanied by the inhibition of the JNK‐MAPK signaling pathway. Mechanistically, SAWPA works in trans as a transcription factor for JNK through the formation of an RNA‐protein complex with HNRNPA1 and MED8 binding the SINE elements upstream of JNK. Therefore, as the first functional SINE‐associated long noncoding RNAs in pigs, SAWPA provides novel insights for the mechanism research on retrotransposons in mammalian pre‐implantation development.