scholarly journals An intracytoplasmic injection of deionized bovine serum albumin immediately after somatic cell nuclear transfer enhances full-term development of cloned mouse embryos

2015 ◽  
Vol 61 (6) ◽  
pp. 503-510 ◽  
Author(s):  
Yuuki ISAJI ◽  
Koki YOSHIDA ◽  
Hiroshi IMAI ◽  
Masayasu YAMADA
Zygote ◽  
2017 ◽  
Vol 26 (1) ◽  
pp. 24-32 ◽  
Author(s):  
Guang-yu Bai ◽  
Si-hang Song ◽  
Yu-wei Zhang ◽  
Xiang Huang ◽  
Xing-wei Huang ◽  
...  

SummarySomatic cell nuclear transfer (SCNT) is an important technique for life science research. However, most SCNT embryos fail to develop to term due to undefined reprogramming defects. Here, we show that abnormal Xi occurs in somatic cell NT blastocysts, whereas in female blastocysts derived from cumulus cell nuclear transfer, both X chromosomes were inactive. H3K27me3 removal by Kdm6a mRNA overexpression could significantly improve preimplantation development of NT embryos, and even reached a 70.2% blastocyst rate of cleaved embryos compared with the 38.5% rate of the control. H3K27me3 levels were significantly reduced in blastomeres from cloned blastocysts after overexpression of Kdm6a. qPCR indicated that rDNA transcription increased in both NT embryos and 293T cells after overexpression of Kdm6a. Our findings demonstrate that overexpression of Kdm6a improved the development of cloned mouse embryos by reducing H3K27me3 and increasing rDNA transcription.


2006 ◽  
Vol 18 (2) ◽  
pp. 124 ◽  
Author(s):  
F. Du ◽  
J. Xu ◽  
S. Gao ◽  
L. Y. Sung ◽  
D. Stone ◽  
...  

Transgenic/knockout (KO) rabbits can serve as an excellent animal model for human cardiovascular diseases (CVD) and other diseases. However, the production of transgenic/KO rabbits is hindered by low efficiency of traditional DNA microinjection and the unavailability of embryonic stem cell lines. An alternative approach is to produce transgenic/KO rabbits by somatic cell nuclear transfer (SCNT) using genetically modified somatic cells as nuclear donors. Our initial objective of the study was to prove the feasibility of cloning rabbits by SCNT because rabbit is a difficult species to be cloned. Rabbit oocytes were flushed from the oviducts of superovulated donors treated with the regime of follicle-stimulating hormone (FSH) and human choriani gonadotropin (hCG). Cumulus cells were then denuded from the oocytes by incubation in 0.5% hyaluronidase and pipetting. Oocyte enucleation was conducted in M199 + 10% fetal bovine serum (FBS) and confirmed by fluorescence microscopy. Cumulus cells used for nuclear donors were prepared from fresh cumulus-oocytes complexes. The donor nucleus was transferred into a recipient oocyte by either cell fusion or direct nuclear injection method. In the cell fusion method, a small donor cell with the diameter approximately 15–19 µm was transferred into the perivitelline space of an enucleated oocyte; subsequently the somatic cell-cytoplast pair was fused by applying three direct current pulses at 3.2 kV/cm for a duration of 20 µs/pulse. In the direct nuclear injection method, a mechanically lysed donor cell was injected into oocyte cytoplasm with the aid of a piezo-drill system. Fused embryos or injected oocytes were activated by the same electrical stimulation regime described above, and subsequently cultured in M199 + 10% FBS containing 2.0 mM 6-dimethylaminopurine (DMAP) and 5 µg/mL cycloheximide for 2 h. For the in vitro study, cloned embryos were cultured in B2 medium plus 2.5% FBS for 5 days (initiation of activation = day 0) at 38.5°C in 5% CO2 humidified air. For the in vivo study, cloned embryos were cultured for 20–22 h in vitro before transfer into pseudopregnant rabbit recipients. Pregnancy was monitored by palpation and/or ultrasound on Days 14–16 post embryo transfer (ET). The results (Table 1) show that the donor nuclei-introducing rate was higher with nuclear direct injection than with the cell fusion method (P < 0.05). There were no significant differences among subsequent cleavage and development to morula and blastocysts between both methods, although the development rates of cloned embryos via electrically mediated fusion were higher than those derived from the injection group. One recipient in the injection group (1/6, 17%) and six recipients in the fusion group (6/16, 38%) were diagnosed as pregnant. From the fusion group, one full-term but stillborn and one live and healthy clone rabbit were delivered on Days 33 and 31 post-ET, respectively. To our knowledge, this is the second report of full term development of cloned rabbit by somatic nuclear transfer cloning. Our further study is to clone live rabbit offspring with modified transgenic/KO somatic cell lines. Table 1. In vitro development of rabbit cloned embryos with cumulus cells as nuclear donors This work was supported by NIH/NCRR-SBIR grant: 1R43RR020261–11.


Zygote ◽  
2004 ◽  
Vol 12 (4) ◽  
pp. 315-320 ◽  
Author(s):  
Man-Xi Jiang ◽  
Cai-Xia Yang ◽  
Li-Sheng Zhang ◽  
Yue-Liang Zheng ◽  
Shu-Zhen Liu ◽  
...  

Conventional methods of somatic cell nuclear transfer either by electrofusion or direct nucleus injection have very low efficiency in animal cloning, especially interspecies cloning. To increase the efficiency of interspecies somatic cell nuclear transfer, in the present study we introduced a method of whole cell intracytoplasmic injection (WCICI) combined with chemical enucleation into panda–rabbit nuclear transfer and assessed the effects of this method on the enucleation rate of rabbit oocytes and the in vitro development and spindle structures of giant panda–rabbit reconstructed embryos. Our results demonstrated that chemical enucleation can be used in rabbit oocytes and the optimal enucleation result can be obtained. When we compared the rates of cleavage and blastocyst formation of subzonal injection (SUZI) and WCICI using chemically enucleated rabbit oocytes as cytoplasm recipients, the rates in the WCICI group were higher than those in the SUZI group, but there was no statistically siginificant difference (p>0.05) between the two methods. The microtubule structures of rabbit oocytes enucleated by chemicals and giant panda–rabbit embryos reconstructed by WCICI combined with chemical enucleation were normal. Therefore the present study suggests that WCICI combined with chemical enucleation can provide an efficient and less labor-intensive protocol of interspecies somatic cell nuclear transfer for producing giant panda cloned embryos.


2012 ◽  
Vol 14 (3) ◽  
pp. 248-257 ◽  
Author(s):  
Kanokwan Srirattana ◽  
Sumeth Imsoonthornruksa ◽  
Chuti Laowtammathron ◽  
Anawat Sangmalee ◽  
Wanchai Tunwattana ◽  
...  

2007 ◽  
Vol 19 (1) ◽  
pp. 212
Author(s):  
K. Ono ◽  
R. Ohishi ◽  
H. Imai ◽  
M. Yamada

Bovine serum albumin (BSA) is an embryotrophic macromolecule used in embryo culture media and improves embryo development in vitro. However, when 1-cell embryos from some strains of mouse were cultured in traditional medium, even with BSA, developmental arrest occurred at the 2-cell stage, termed '2-cell block'. The developmental block is known to be alleviated by adding EDTA to the medium for ICR and ddY strains, and deleting phosphate from the medium for the AKR strain. Recently, our preliminary experiments revealed that the 2-cell block is relieved by adding deionized BSA (d-BSA) to the medium for the ICR strain. Thus, in the present study, we investigated whether d-BSA could rescue the embryos from ICR, ddY, and AKR strains from the 2-cell block. Fertilized 1-cell embryos were collected 20 h post-hCG from superovulated ICR, ddY, and AKR females (8-week-old) that had been mated with the ICR strain of males. Stock solutions (15%) of commercially available fraction V BSA, ovalbumin (ova), and γ-globulin (γG) were deionized over a mixed-bed ion adsorption resin. Embryos were cultured in EDTA-depleted KSOM medium with or without these deionized or non-deionized proteins at 37�C under 5% CO2 in air for 4 days. Experiments were done in at least 3 replicates, and the statistical analyses of the data were done by ANOVA and Fisher&apos;s PLDS test. To observe the distribution of BSA in the embryos from the 1-cell to the blastocyst stages, immunofluorescence study was performed using anti-BSA antibody with a laser confocal microscope. The developmental rates to the 4-cell stage of 1-cell embryos cultured in medium without (control group) or with BSA at 0.3% in ICR and 0.6% in ddY and AKR (BSA group) were very low (ICR: 10% (4/38) and 37% (17/47); ddY: 9% (7/73) and 23% (9/37); AKR: 0% (0/60) and 0% (18/30), respectively). However, when embryos were cultured with d-BSA at 0.3% in ICR and 0.6% in ddY and AKR, the rates to the 4-cell stage significantly increased (ICR: 91% (51/56), ddY: 82% (61/76), AKR: 82% (50/60) vs. control group or BSA group: P &lt; 0.05), and development to the blastocyst stage was observed (ICR: 79% (44/56), ddY: 65% (47/76), AKR: 63% (38/60)). When ICR embryos were cultured with 0.3% deionized-ova or deionized-�G, no significant increase was observed in developmental rates to the 4-cell stage (25% (10/40) and 24% (10/42), respectively). We next examined the critical culture period for the beneficial effects of d-BSA and intracellular distribution of BSA using ddY mouse embryos. It was found that exposure to d-BSA during the late 1-cell (24 h post-hCG) and early 2-cell stages (42 h post-hCG) promoted the development beyond the 2-cell stage. The distribution of BSA in the cytoplasm of embryos at any stage was observed. Interestingly, BSA localized in the nuclei of embryos during the late 1-cell and early 2-cell stages. In conclusion, our results suggest that BSA itself has a potential to remove the 2-cell block in ICR, ddY, and AKR strains. In addition, nuclear localization of BSA may play a key role in regulating the development beyond the 2-cell stage in the mouse embryos.


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