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Lopukhov AV, Singina GN, Zinovieva NA. Biotechnological bases of the development of cloned pig embryos. Vavilovskii Zhurnal Genet Selektsii 2019. [DOI: 10.18699/vj19.521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The term ‘clone’ in animal biotechnology refers to an organism derived from non-sexual reproduction, which is both a direct offspring and a genetic copy of the parent organism. To date, the pig appears to be the most interesting object in cloning research. Somatic cell nuclear transfer in pigs has a wide range of potential applications in various fields of human scientific and economic activities. However, the efficiency of producing cloned embryos in swine is still lower than that of other livestock species, in particular horses and cattle. Somatic cell nuclear transfer is a technically complex multi-stage technology, at each stage of which the pig oocytes, which are more susceptible to changes of surrounding conditions, are affected by various factors (mechanical, physical, chemical). At the stage of oocyte maturation, changes in the cell ultrastructures of the ooplasm occur, which play an important role in the subsequent nuclear reprogramming of the transferred donor cell. Before transfer to the oocyte donor somatic cells are synchronized in the G0/G1 stage of the cell cycle to ensure the normal ploidy of the cloned embryo. When removing the nucleus of pig oocytes maturated in vitro, it is necessary to pay attention to the problem of preserving the viability of cells, which were devoid of their own nuclear material. To perform the reconstruction, a somatic cell is placed, using micro-tools, in the perivitelline space, where the first polar body was previously located, or in the cytoplasm of an enucleated oocyte. The method of manual cloning involves the removal of the oocyte nucleus with subsequent fusion with the donor cell without the use of micromanipulation techniques. The increased sensitivity of oocytes to the environmental conditions causes special requirements for the choice of the system for in vitro culture of cloned pig embryos. In this work, we have reviewed the modern methods used for the production of cloned embryos and identified the technological issues that prevent improving the efficiency of somatic cloning of pigs.
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Affiliation(s)
- A. V. Lopukhov
- Federal Science Center for Animal Husbandry named after Academy Member L.K. Ernst
| | - G. N. Singina
- Federal Science Center for Animal Husbandry named after Academy Member L.K. Ernst
| | - N. A. Zinovieva
- Federal Science Center for Animal Husbandry named after Academy Member L.K. Ernst
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Kim E, Zheng Z, Jeon Y, Jin YX, Hwang SU, Cai L, Lee CK, Kim NH, Hyun SH. An Improved System for Generation of Diploid Cloned Porcine Embryos Using Induced Pluripotent Stem Cells Synchronized to Metaphase. PLoS One 2016; 11:e0160289. [PMID: 27472781 PMCID: PMC4966966 DOI: 10.1371/journal.pone.0160289] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 07/15/2016] [Indexed: 12/29/2022] Open
Abstract
Pigs provide outstanding models of human genetic diseases due to their striking similarities with human anatomy, physiology and genetics. Although transgenic pigs have been produced using genetically modified somatic cells and nuclear transfer (SCNT), the cloning efficiency was extremely low. Here, we report an improved method to produce diploid cloned embryos from porcine induced pluripotent stem cells (piPSCs), which were synchronized to the G2/M stage using a double blocking method with aphidicolin and nocodazole. The efficiency of this synchronization method on our piPSC lines was first tested. Then, we modified our traditional SCNT protocol to find a workable protocol. In particular, the removal of a 6DMAP treatment post-activation enhanced the extrusion rate of pseudo-second-polar bodies (p2PB) (81.3% vs. 15.8%, based on peak time, 4hpa). Moreover, an immediate activation method yielded significantly more blastocysts than delayed activation (31.3% vs. 16.0%, based on fused embryos). The immunofluorescent results confirmed the effect of the 6DMAP treatment removal, showing remarkable p2PB extrusion during a series of nuclear transfer procedures. The reconstructed embryos from metaphase piPSCs with our modified protocol demonstrated normal morphology at 2-cell, 4-cell and blastocyst stages and a high rate of normal karyotype. This study demonstrated a new and efficient way to produce viable cloned embryos from piPSCs when synchronized to the G2/M phase of the cell cycle, which may lead to opportunities to produce cloned pigs from piPSCs more efficiently.
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Affiliation(s)
- Eunhye Kim
- Laboratory of Veterinary Embryology and Biotechnology, (VETEMBIO), Veterinary Medical Center and Collage of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea
- Institute for Stem Cell & Regenerative Medicine (ISCRM), Chungbuk National University, Cheongju, Chungbuk, Republic of Korea
| | - Zhong Zheng
- Laboratory of Veterinary Embryology and Biotechnology, (VETEMBIO), Veterinary Medical Center and Collage of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea
| | - Yubyeol Jeon
- Laboratory of Veterinary Embryology and Biotechnology, (VETEMBIO), Veterinary Medical Center and Collage of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea
| | - Yong-Xun Jin
- Department of Animal Sciences, Agriculture, Life, & Environmental Sciences, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea
| | - Seon-Ung Hwang
- Laboratory of Veterinary Embryology and Biotechnology, (VETEMBIO), Veterinary Medical Center and Collage of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea
- Institute for Stem Cell & Regenerative Medicine (ISCRM), Chungbuk National University, Cheongju, Chungbuk, Republic of Korea
| | - Lian Cai
- Laboratory of Veterinary Embryology and Biotechnology, (VETEMBIO), Veterinary Medical Center and Collage of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea
| | - Chang-Kyu Lee
- Department of Agricultural Biotechnology, Research Institute for Agriculture and Life Science, Seoul National University, Seoul, Republic of Korea
| | - Nam-Hyung Kim
- Department of Animal Sciences, Agriculture, Life, & Environmental Sciences, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea
| | - Sang-Hwan Hyun
- Laboratory of Veterinary Embryology and Biotechnology, (VETEMBIO), Veterinary Medical Center and Collage of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea
- Institute for Stem Cell & Regenerative Medicine (ISCRM), Chungbuk National University, Cheongju, Chungbuk, Republic of Korea
- * E-mail:
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Park SK, Roh S, Park JI. A simplified one-step nuclear transfer procedure alters the gene expression patterns and developmental potential of cloned porcine embryos. J Vet Sci 2013; 15:73-80. [PMID: 23820223 PMCID: PMC3973768 DOI: 10.4142/jvs.2014.15.1.73] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 06/28/2013] [Indexed: 12/25/2022] Open
Abstract
Various somatic cell nuclear transfer (SCNT) techniques for mammalian species have been developed to adjust species-specific procedures to oocyte-associated differences among species. Species-specific SCNT protocols may result in different expression levels of developmentally important genes that may affect embryonic development and pregnancy. In the present study, porcine oocytes were treated with demecolcine that facilitated enucleation with protruding genetic material. Enucleation and donor cell injection were performed either simultaneously with a single pipette (simplified one-step SCNT; SONT) or separately with different pipettes (conventional two-step SCNT; CTNT) as the control procedure. After blastocysts from both groups were cultured in vitro, the expression levels of developmentally important genes (OCT4, NANOG, EOMES, CDX2, GLUT-1, PolyA, and HSP70) were analyzed by real-time quantitative polymerase chain reaction. Both the developmental rate according to blastocyst stage as well as the expression levels CDX2, EOMES, and HSP70 were elevated with SONT compared to CTNT. The genes with elevated expression are known to influence trophectoderm formation and heat stress-induced arrest. These results showed that our SONT technique improved the development of SCNT porcine embryos, and increased the expression of genes that are important for placental formation and stress-induced arrest.
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Affiliation(s)
- Sang Kyu Park
- Cellular Reprogramming and Embryo Biotechnology Laboratory, Dental Research Institute, Seoul National University School of Dentistry, Seoul 110-749, Korea
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