State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China.
College of Life Science and Technology, Guangxi University, Nanning, China.
Reprod Domest Anim. 2021 Jul;56(7):992-1003. doi: 10.1111/rda.13942. Epub 2021 May 3.
Suppressor of variegation 3-9 homolog (Suv39h)1 and 2, Histone H3 lysine 9 trimethylation (H3K9me3)-specific methyltransferases, are mainly involved in regulating the dynamic changes of H3K9me3. Regulating Suv39h expression influences the early development of mice somatic cell nuclear transfer (SCNT) embryos, there are few reports concerning their features in domestic animals. The aim of the present study was to characterize the Suv39h function in early development of Debao porcine SCNT embryos. The global level of H3K9me3 and the expression profiles of Suv39h1/2 in porcine early embryos were analysed by immunohistochemistry and qRT-PCR methods, respectively. Their roles in cell proliferation and histone modification of Debao porcine foetal fibroblast cells (PFFs), and developmental competence of porcine SCNT embryos were investigated by shRNA technology. The methylation levels of H3K9me3 and the expression patterns of Suv39h1 and Suv39h2 were similar (p < .05), and both of them displayed higher levels in Debao porcine SCNT embryos compared with that in PA embryos. The global levels of H3K9me3 and the expressions of G9a, HDAC1 and DNMT1 were decreased by combined inhibition of Suv39h1 and Suv39h2 (p < .05), while the expression of HAT1 was increased (p < .05). Downregulation of Suv39h1/2 also promoted cell proliferation and resulted in a significant increase in the expression of CyclinA2, CyclinB and PCNA in PFFs (p < .05). Furthermore, the use of donor somatic nuclei which depleted H3K9me3 by inhibiting Suv39h1/2 expression markedly increased the cleavage rate, the blastocyst rate and the total cell number of blastocysts of Debao porcine SCNT embryos (p < .05). Altogether, the above results indicate that H3K9me3 levels and Suv39h1/2 expressions display similar patterns in porcine early embryo, and low levels of them are critical to cell proliferation of PFFs and early development of SCNT embryos.
沉默调节蛋白 3-9 同源物（Suv39h）1 和 2 是组蛋白 H3 赖氨酸 9 三甲基化（H3K9me3）特异性甲基转移酶，主要参与调节 H3K9me3 的动态变化。调节 Suv39h 的表达会影响小鼠体细胞核移植（SCNT）胚胎的早期发育，而关于其在家畜中的特征的报道很少。本研究旨在表征 Debao 猪 SCNT 胚胎早期发育中 Suv39h 的功能。通过免疫组织化学和 qRT-PCR 方法分别分析了猪早期胚胎中 H3K9me3 的整体水平和 Suv39h1/2 的表达谱。通过 shRNA 技术研究了它们在 Debao 猪胎儿成纤维细胞（PFF）中的细胞增殖和组蛋白修饰作用以及猪 SCNT 胚胎的发育能力。H3K9me3 的甲基化水平和 Suv39h1 和 Suv39h2 的表达模式相似（p<.05），并且它们在 Debao 猪 SCNT 胚胎中的表达水平均高于 PA 胚胎。H3K9me3 的整体水平以及 G9a、HDAC1 和 DNMT1 的表达水平通过抑制 Suv39h1 和 Suv39h2 的联合抑制而降低（p<.05），而 HAT1 的表达水平增加（p<.05）。下调 Suv39h1/2 也促进了细胞增殖，并导致 PFF 中 CyclinA2、CyclinB 和 PCNA 的表达显著增加（p<.05）。此外，使用抑制 Suv39h1/2 表达耗尽 H3K9me3 的供体细胞核可显著提高 Debao 猪 SCNT 胚胎的卵裂率、囊胚率和囊胚总细胞数（p<.05）。总之，上述结果表明，猪早期胚胎中 H3K9me3 水平和 Suv39h1/2 表达呈现相似的模式，低水平的 H3K9me3 对于 PFF 的细胞增殖和 SCNT 胚胎的早期发育至关重要。
