DZNep and UNC0642 enhance in vitro developmental competence of cloned pig embryos

Abstract

Somatic cell nuclear transfer in mammalian cloning suffers from a faulty epigenetic reprogramming, which is believed to cause developmental failures in cloned embryos. Regulating the epigenetic-modifying enzymes can rescue the chromatin of cloned embryos from aberrant epigenetic status, thereby potentially promoting cloning efficiency. In this study, we investigated the effect of two histone methyltransferase inhibitors, namely, DZNep and UNC0642, on the in vitro developmental competence of cloned pig embryos. We found that (1) treatment with 10 nM DZNep or 5 nM UNC0642 for 24 h after activation had the best promoting effect on the development of cloned embryos (blastocyst rate 10.32% vs 18.08% for DZNep, and 10.44% vs 18.14% for UNC0642); (2) 10 nM DZNep and 5 nM UNC0642 significantly decreased the levels of H3K27me3 and H3K9me2, respectively, at the 2-cell, 4-cell and blastocyst stages; (3) the apoptosis level was lower in the treatment groups than in untreated control; and (4) the transcriptional expression of epigenetic genes (EZH2, GLP, G9a, Setdb1, Setdb2, Suv39h1 and Suv39h2) was decreased and pluripotency genes (Nanog, Pou5f1, Sox2 and Bmp4) was increased in treatment groups compared with control. These results indicated that treatment with DZNep and UNC0642 improves the epigenetic reprogramming of cloned embryos, which could render beneficial effect on the embryo quality and aberrant gene expression, and finally improve the developmental competence of cloned pig embryos.

Ex Situ Conservation and Genetic Rescue of Endangered Polish Cattle and Pig Breeds with the Aid of Modern Reproductive Biotechnology – A Review

“…The efficiency of generating bovine nuclear-transferred (NT) embryos reconstructed with Polish Red cattle ear explant-derived dermal fibroblast cells (EE-DFCs) to reach the blastocyst stage in vitro (30.1%) was comparable to, or remarkably higher than, that reported by other investigators (Qu et al, 2017;Glanzner et al, 2018;Xu et al, 2019;Zhou et al, 2019). Analogously, the capabilities of porcine NT embryos reconstructed with Puławska or Złotnicka Spotted pig EE-DFCs to complete their extracorporeal development to the blastocyst stage (Puławska: 34.1% and Złotnicka Spotted: 27.9%, respectively) were similar to, or considerably higher than, those noticed in other studies (Glanzner et al, 2018;Zhao et al, 2018;Taweechaipaisankul et al, 2019;Jeong et al, 2020;Qu et al, 2020). Samiec et al (2020).…”

Chaetocin Improves Pig Cloning Efficiency by Enhancing Epigenetic Reprogramming and Autophagic Activity

“…Moreover, SCNT embryos are typically transferred to the recipient oviduct as early as the one- or two-cell stage because of the reduced efficiency of in vitro culture conditions compared to in vivo [ 35 , 36 ]. For these reasons, the application of histone and DNA methyltransferase inhibitors, such as BIX-01294, MM-102, RG108, DZNep, and UNC0642, at the early stages after activation accelerates the in vitro development of SCNT embryos [ 37 , 38 , 39 , 40 ]. In this study, treatment with 0.5 nM chaetocin for 24 h after activation significantly enhanced the developmental competence of porcine SCNT embryos in terms of the cleavage rate, blastocyst formation rate, hatching rate, total cell number, and cell survival rate.…”

Challenges and Considerations during In Vitro Production of Porcine Embryos

“…While there are reports of epigenetic control over transcription, it is not clear if the changes in DNA methylation, for example, are the result of or the cause of changes in transcription [197][198][199][200]. In pigs, epigenetic regulation of development is not limited to DNA methylation and includes histone modifications, such as acetylation [201], methylation [202,203], and RNA methylation [204]. Much work has been reported on epigenetic regulation in pig development and after SCNT [205,206].…”