Animal Reproduction Institute, State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning530005, P.R. China.
Center of Reproductive Medicine, Guangxi Maternal and Child Health Hospital, Nanning530003, P.R. China.
Microsc Microanal. 2021 Apr;27(2):409-419. doi: 10.1017/S1431927620024964.
Somatic cell nuclear transfer (SCNT) holds vast potential in agriculture. However, its applications are still limited by its low efficiency. Histone 3 lysine 9 trimethylation (H3K9me3) was identified as an epigenetic barrier for this. Histone demethylase KDM4D could regulate the level of H3K9me3. However, its effects on buffalo SCNT embryos are still unclear. Thus, we performed this study to explore the effects and underlying mechanism of KDM4D on buffalo SCNT embryos. The results revealed that compared with the IVF embryos, the expression level of KDM4D in SCNT embryos was significantly lower at 8- and 16-cell stage, while the level of H3K9me3 in SCNT embryos was significantly higher at 2-cell, 8-cell, and blastocyst stage. Microinjection of KDM4D mRNA could promote the developmental ability of buffalo SCNT embryos. Furthermore, the expression level of ZGA-related genes such as ZSCAN5B, SNAI1, eIF-3a, and TRC at the 8-cell stage was significantly increased. Meanwhile, the pluripotency-related genes like POU5F1, SOX2, and NANOG were also significantly promoted at the blastocyst stage. The results were reversed after KDM4D was inhibited. Altogether, these results revealed that KDM4D could correct the H3K9me3 level, increase the expression level of ZGA and pluripotency-related genes, and finally, promote the developmental competence of buffalo SCNT embryos.
体细胞核移植（SCNT）在农业中有巨大的应用潜力。然而，其应用仍然受到低效率的限制。组蛋白 3 赖氨酸 9 三甲基化（H3K9me3）被认为是这一过程的表观遗传障碍。组蛋白去甲基化酶 KDM4D 可以调节 H3K9me3 的水平。然而，其对水牛 SCNT 胚胎的影响尚不清楚。因此，我们进行了这项研究，以探讨 KDM4D 对水牛 SCNT 胚胎的影响及其潜在机制。结果表明，与 IVF 胚胎相比，SCNT 胚胎在 8 细胞和 16 细胞期的 KDM4D 表达水平显著降低，而 H3K9me3 的水平在 2 细胞、8 细胞和囊胚期显著升高。KDM4D mRNA 的微注射可以促进水牛 SCNT 胚胎的发育能力。此外，ZGA 相关基因如 ZSCAN5B、SNAI1、eIF-3a 和 TRC 在 8 细胞期的表达水平显著增加。同时，多能性相关基因如 POU5F1、SOX2 和 NANOG 在囊胚期也显著上调。抑制 KDM4D 后，结果发生逆转。综上所述，这些结果表明 KDM4D 可以纠正 H3K9me3 水平，增加 ZGA 和多能性相关基因的表达水平，最终促进水牛 SCNT 胚胎的发育能力。
