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The effect of Xenopus laevis egg extracts with/without BRG1 on the development of preimplantation cloned mouse embryos: Cite this article: Chien-Yueh Chiang et al. (2019) The effect of Xenopus laevis egg extracts with/without BRG1 on the development of preimplantation cloned mouse embryos. Zygote27: 143–152. doi: 10.1017/S0967199419000091

  • Chien-Yueh Chiang (a1), Xin-Yu Chen (a1), Chun-Ting Lin (a1) and Pin-Chi Tang (a1) (a2) (a3)


Much effort has been devoted to improving the efficiency of animal cloning. The aim of this study was to investigate the effect of BRG1 contained in Xenopus egg extracts on the development of cloned mouse embryos. The results showed that mouse NIH/3T3 cells were able to express pluripotent genes after treatment with egg extracts, indicating that the egg extracts contained reprogramming factors. After co-injection of Xenopus egg extracts and single mouse cumulus cells into enucleated mouse oocytes, statistically higher pronucleus formation and development rates were observed in the egg Extract− co-injected group compared with those in the no egg extract-injected (NT) group (38–66% vs 18–34%, P<0.001). Removal of BRG1 protein from Xenopus egg extracts was conducted, and the BRG1-depleted extracts were co-injected with single donor cells into recipient oocytes. The results showed that the percentages of pronucleus formation were significantly higher in both BRG1-depleted and BRG1-intact groups than that in the nuclear transfer (NT) group (94, 64% vs 50%, P<0.05). Furthermore, percentages in the BRG1-depleted group were even higher than in the BRG1-intact group (94% vs 64%). More confined expression of Oct4 in the inner cell mass (ICM) was observed in the blastocyst derived from the egg extract-injected groups. However, Nanog expression was more contracted in the ICM of cloned blastocysts in the BRG1-depleted group than in the BGR1-intact group. Based on the present study, BRG1 might not play an essential role in reprogramming, but the factors enhancing pronucleus formation and development of cloned mouse embryos are contained in Xenopus egg extracts.


Corresponding author

*Address for correspondence: Pin-Chi Tang. National Chung Hsing University, Taichung, 402, Taiwan. Tel: +886 4 22857109. Fax: +886 4 22860265. E-mail:


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These authors contributed equally to this work.



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Alberio, R, Johnson, AD, Stick, R and Campbell, KH (2005) Differential nuclear remodeling of mammalian somatic cells by Xenopus laevis oocyte and egg cytoplasm. Exp Cell Res 307, 131141.
Bian, Y, Alberio, R, Allegrucci, C, Campbell, KH and Johnson, AD (2009) Epigenetic marks in somatic chromatin are remodelled to resemble pluripotent nuclei by amphibian oocyte extracts. Epigenetics 4, 194202.
Bongso, A, Fong, CY and Gauthaman, K (2008) Taking stem cells to the clinic: major challenges. J Cell Biochem 105, 13521360.
Bui, HT, Kwon, DN, Kang, MH, Oh, MH, Park, MR, Park, WJ, Paik, SS, Van Thuan, N and Kim, JH (2012) Epigenetic reprogramming in somatic cells induced by extract from germinal vesicle stage pig oocytes. Development 139, 43304340.
Bultman, S, Gebuhr, T, Yee, D, La Mantia, C, Nicholson, J, Gilliam, A, Randazzo, F, Metzger, D, Chambon, P, Crabtree, G and Magnuson, T (2000) A Brg1 null mutation in the mouse reveals functional differences among mammalian SWI/SNF complexes. Mol Cell 6, 12871295.
Bultman, SJ, Gebuhr, TC, Pan, H, Svoboda, P, Schultz, RM and Magnuson, T (2006) Maternal BRG1 regulates zygotic genome activation in the mouse. Genes Dev 20, 17441754.
Byrne, JA, Simonsson, S, Western, PS and Gurdon, JB (2003) Nuclei of adult mammalian somatic cells are directly reprogrammed to Oct-4 stem cell gene expression by amphibian oocytes. Curr Biol 13, 12061213.
Campbell, KH (2007) Ten years of cloning: questions answered and personal reflections. Cloning Stem Cells 9, 811.
Campbell, KH, Fisher, P, Chen, WC, Choi, I, Kelly, RD, Lee, JH and Xhu, J (2007) Somatic cell nuclear transfer: Past, present and future perspectives. Theriogenology 68(Suppl 1), S214S231.
Carey, TS, Cao, Z, Choi, I, Ganguly, A, Wilson, CA, Paul, S and Knott, JG (2015) BRG1 governs nanog transcription in early mouse embryos and embryonic stem cells via antagonism of histone H3 lysine 9/14 acetylation. Mol Cell Biol 35, 41584169.
Chatot, CL, Ziomek, CA, Bavister, BD, Lewis, JL and Torres, I (1989) An improved culture medium supports development of random-bred 1-cell mouse embryos in vitro. J Reprod Fertil 86, 679688.
Check, E (2007) Cloning special: Dolly: a hard act to follow. Nature 445, 802.
Chickarmane, V, Troein, C, Nuber, UA, Sauro, HM and Peterson, C (2006) Transcriptional dynamics of the embryonic stem cell switch. PLoS Comput Biol 2, e123.
Cowan, CA, Atienza, J, Melton, DA and Eggan, K (2005) Nuclear reprogramming of somatic cells after fusion with human embryonic stem cells. Science 309, 13691373.
Duinsbergen, D, Eriksson, M, ’t Hoen, PA, Frisén, J and Mikkers, H (2008) Induced pluripotency with endogenous and inducible genes. Exp Cell Res 314, 32553263.
Gomez, MC, Pope, CE, Giraldo, A, Lyons, LA, Harris, RF, King, AL, Cole, A, Godke, RA and Dresser, BL (2004) Birth of African Wildcat cloned kittens born from domestic cats. Cloning Stem Cells 6, 247258.
Gomez, MC, Pope, CE, Ricks, DM, Lyons, J, Dumas, C and Dresser, BL (2009) Cloning endangered felids using heterospecific donor oocytes and interspecies embryo transfer. Reprod Fertil Dev 21, 7682.
Hansis, C (2006) Totipotency, cell differentiation and reprogramming in humans. Reprod Biomed Online 13, 551557.
Hansis, C, Barreto, G, Maltry, N and Niehrs, C (2004) Nuclear reprogramming of human somatic cells by Xenopus egg extract requires BRG1. Curr Biol 14, 14751480.
Hochedlinger, K and Jaenisch, R (2006) Nuclear reprogramming and pluripotency. Nature 441, 10611067.
Jullien, J, Astrand, C, Halley-Stott, RP, Garrett, N and Gurdon, JB (2010) Characterization of somatic cell nuclear reprogramming by oocytes in which a linker histone is required for pluripotency gene reactivation. Proc Natl Acad Sci USA 107, 54835488.
Jullien, J, Pasque, V, Halley-Stott, RP, Miyamoto, K and Gurdon, JB (2011) Mechanisms of nuclear reprogramming by eggs and oocytes: a deterministic process? Nat Rev Mol Cell Biol 12, 453459.
Kidder, BL, Palmer, S and Knott, JG (2009) SWI/SNF-Brg1 regulates self-renewal and occupies core pluripotency-related genes in embryonic stem cells. Stem Cells 27, 317328.
Kim, JB, Zaehres, H, Wu, G, Gentile, L, Ko, K, Sebastiano, V, Araúzo-Bravo, MJ, Ruau, D, Han, DW, Zenke, M and Schöler, HR (2008) Pluripotent stem cells induced from adult neural stem cells by reprogramming with two factors. Nature 454, 646650.
Koziol, MJ, Garrett, N and Gurdon, JB (2007) Tpt1 activates transcription of oct4 and nanog in transplanted somatic nuclei. Curr Biol 17, 801–7.
Loi, P, Ptak, G, Barboni, B, Fulka, J Jr, Cappai, P and Clinton, M (2001) Genetic rescue of an endangered mammal by cross-species nuclear transfer using post-mortem somatic cells. Nat Biotechnol 19, 962964.
Markoulaki, S, Meissner, A and Jaenisch, R (2008) Somatic cell nuclear transfer and derivation of embryonic stem cells in the mouse. Methods 45, 101114.
McLean, CA, Wang, Z, Babu, K, Edwards, A, Kasinathan, P, Robl, J and Sheppard, AM (2010) Normal development following chromatin transfer correlates with donor cell initial epigenetic state. Anim Reprod Sci 118(24), 388393.
Miyamoto, K, Furusawa, T, Ohnuki, M, Goel, S, Tokunaga, T, Minami, N, Yamada, M, Ohsumi, K and Imai, H (2007) Reprogramming events of mammalian somatic cells induced by Xenopus laevis egg extracts. Mol Reprod Dev 74, 12681277.
Miyamoto, K, Yamashita, T, Tsukiyama, T, Kitamura, N, Minami, N, Yamada, M and Imai, H (2008) Reversible membrane permeabilization of mammalian cells treated with digitonin and its use for inducing nuclear reprogramming by Xenopus egg extracts. Cloning Stem Cells 10, 535542.
Miyamoto, K, Tsukiyama, T, Yang, Y, Li, N, Minami, N, Yamada, M and Imai, H (2009) Cell-free extracts from mammalian oocytes partially induce nuclear reprogramming in somatic cells. Biol Reprod 80, 935943.
Okita, K, Ichisaka, T and Yamanaka, S (2007) Generation of germline-competent induced pluripotent stem cells. Nature 448, 313317.
Pasque, V, Jullien, J, Miyamoto, K, Halley-Stott, RP and Gurdon, JB (2011) Epigenetic factors influencing resistance to nuclear reprogramming. Trends Genet 27, 516525.
Prelle, K, Zink, N and Wolf, E (2002) Pluripotent stem cells – model of embryonic development, tool for gene targeting, and basis of cell therapy. Anat Histol Embryol 31, 169186.
Reik, W, Dean, W and Walter, J (2001) Epigenetic reprogramming in mammalian development. Science 293, 10891093.
Reik, W, Santos, F and Dean, W (2003) Mammalian epigenomics: reprogramming the genome for development and therapy. Theriogenology 59, 2132.
Singhal, N, Graumann, J, Wu, G, Araúzo-Bravo, MJ, Han, DW, Greber, B, Gentile, L, Mann, M and Schöler, HR (2010) Chromatin-remodeling components of the BAF complex facilitate reprogramming. Cell 141, 943955.
Tada, M, Takahama, Y, Abe, K, Nakatsuji, N and Tada, T (2001) Nuclear reprogramming of somatic cells by in vitro hybridization with ES cells. Curr Biol 11, 15531558.
Tadros, W and Lipshitz, HD (2009) The maternal-to-zygotic transition: a play in two acts. Development 136, 30333042.
Takahashi, K and Yamanaka, S (2006) Induction of pluripotent stem cells from mouse embryonic and adult fibroblast cultures by defined factors. Cell 126, 663676.
Takebayashi, S, Lei, I, Ryba, T, Sasaki, T, Dileep, V, Battaglia, D, Gao, X, Fang, P, Fan, Y, Esteban, MA, Tang, J, Crabtree, GR, Wang, Z and Gilbert, DM (2013) Murine esBAF chromatin remodeling complex subunits BAF250a and Brg1 are necessary to maintain and reprogram pluripotency-specific replication timing of select replication domains. Epigenetics Chromatin 6, 42.
Tamada, H, Van Thuan, N, Reed, P, Nelson, D, Katoku-Kikyo, N, Wudel, J, Wakayama, T and Kikyo, N (2006) Chromatin decondensation and nuclear reprogramming by nucleoplasmin. Mol Cell Biol 26, 12591271.
Tang, S, Wang, Y, Zhang, D, Gao, Y, Ma, Y, Yin, B, Sun, J, Liu, J and Zhang, Y (2009) Reprogramming donor cells with oocyte extracts improves in vitro development of nuclear transfer embryos. Anim Reprod Sci 115, 19.
Trotter, KW and Archer, TK (2008) The BRG1 transcriptional coregulator. Nucl Recept Signal 6, e004.
Wadman, M (2007) Cloning special: Dolly: a decade on. Nature, 445, 800801.
Wakayama, T and Yanagimachi, R (1998) The first polar body can be used for the production of normal offspring in mice. Biol Reprod 59, 100104.
Wernig, M, Meissner, A, Foreman, R, Brambrink, T, Ku, M, Hochedlinger, K, Bernstein, BE and Jaenisch, R (2007) In vitro reprogramming of fibroblasts into a pluripotent ES-cell-like state. Nature 448, 318324.
Wilmut, I, Schnieke, AE, McWhir, J, Kind, AJ and Campbell, KH (1997) Viable offspring derived from fetal and adult mammalian cells. Nature 385, 810813.
Yang, X, Mao, J, Walters, EM, Zhao, MT, Teson, J, Lee, K and Prather, RS (2012) Xenopus egg extract treatment reduced global DNA methylation of donor cells and enhanced somatic cell nuclear transfer embryo development in pigs. Biores. Open Access 1, 7987.



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