Nuclear reprogramming of cloned embryos and its implications for therapeutic cloning

Yang, Xiangzhong; Smith, Sadie; Tian, X. Cindy; Lewin, Harris A.; Renard, Jean‐Paul; Wakayama, Teruhiko

doi:10.1038/ng1973

Cited by 534 publications

(466 citation statements)

References 91 publications

Supporting

Mentioning

440

Contrasting

Unclassified

Order By: Relevance

“…Even though the pig SCNT procedure has been developed for over 10 years and a large number of cloned pigs have been produced, this approach is still inefficient. The cloning efficiency (number of live born cloned piglets/number of reconstructed embryos) is usually around 1-3% (Whitworth and Prather 2010;Yang et al, 2007;Zhao et al, 2010). This low success rate is considered to be the major problem that limits extensive application of the SCNT technique in pigs.…”

Section: Introductionmentioning

confidence: 99%

Effects of Donor Fibroblast Cell Type and Transferred Cloned Embryo Number on the Efficiency of Pig Cloning

Shi

Liu

et al. 2013

Cellular Reprogramming

View full text Add to dashboard Cite

Currently, cloning efficiency in pigs is very low. Donor cell type and number of cloned embryos transferred to an individual surrogate are two major factors that affect the successful rate of somatic cell nuclear transfer (SCNT) in pigs. This study aimed to compare the influence of different donor fibroblast cell types and different transferred embryo numbers on recipients' pregnancy rate and delivery rate, the average number of total clones born, clones born alive and clones born healthy per litter, and the birth rate of healthy clones ( = total number of healthy cloned piglets born / total number of transferred cloned embryos). Three types of donor fibroblasts were tested in large-scale production of cloned pigs, including fetal fibroblasts (FFBs) from four genetically similar Western swine breeds of Pietrain (P), Duroc (D), Landrace (L), and Yorkshire (Y), which are referred to as P,D,LY-FFBs, adult fibroblasts (AFBs) from the same four breeds, which are designated P,D,L,Y-AFBs, and AFBs from a Chinese pig breed of Laiwu (LW), which is referred to as LW-AFBs. Within each donor fibroblast cell type group, five transferred cloned embryo number groups were tested. In each embryo number group, 150-199, 200-249, 250-299, 300-349, or 350-450 cloned embryos were transferred to each individual recipient sow. For the entire experiment, 92,005 cloned embryos were generated from nearly 115,000 matured oocytes and transferred to 328 recipients; in total, 488 cloned piglets were produced. The results showed that the mean clones born healthy per litter resulted from transfer of embryos cloned from LW-AFBs (2.53 -0.34) was similar with that associated with P,D,L,Y-FFBs (2.72 -0.29), but was significantly higher than that resulted from P,D,L,Y-AFBs (1.47 -0.18). Use of LW-AFBs as donor cells for SCNT resulted in a significantly higher pregnancy rate (72.00% vs. 59.30% and 48.11%) and delivery rate (60.00% vs. 45.93% and 35.85%) for cloned embryo recipients, and a significantly higher birth rate of healthy clones (0.5009% vs. 0.3362% and 0.2433%) than that resulting from P,D,L,Y-AFBs and P,D,L,Y-FFBs. This suggests that using LW-AFBs as donor cells results in a higher cloning efficiency in pigs, compared with the other two donor fibroblast cell types. The birth rate of healthy clones was significantly improved when the number of transferred cloned embryos was increased from 150-199 to 200-450 per recipient. However, increase of the number of transferred embryos from 200-249 to 250-450 per surrogate did not change the birth rate of healthy clones. This suggests that transfer of excessive (250-450) cloned embryos to an individual surrogate is not necessary for increasing the cloning efficiency in pigs, and the relatively optimal number of reconstructed embryos transferred to individual recipient is 200-249. Furthermore, our results indicated that the numbers of total born clones, clones born alive, and clones born healthy per litter have a significantly high positive correlation with each other. The present study provi...

show abstract

Section: Introductionmentioning

confidence: 99%

Effects of Donor Fibroblast Cell Type and Transferred Cloned Embryo Number on the Efficiency of Pig Cloning

Shi

Liu

et al. 2013

Cellular Reprogramming

View full text Add to dashboard Cite

show abstract

“…Let's fake a mammoth expression 10 . The recent discovery that the nuclei of normal body cells can be induced into an embryonic-like state without the need for nuclear transfer will help researchers to understand the effect of these epigenetic signals and how to manipulate them, she says.…”

Section: Hnmentioning

confidence: 99%

Darwin 200: Let's make a mammoth

Nicholls¹

2008

Nature

View full text Add to dashboard Cite

“…Recent studies demonstrated that abnormal gene expression and epigenetic modification are related to early abortion during mid-gestation and a low birth ratio of cloned animals [2][3][4]. Imprinted genes are specifically expressed by one of the two homologous chromosomes and contain parent-origin genetic information.…”

Section: Introductionmentioning

confidence: 99%

Altered imprinted gene expression and methylation patterns in mid-gestation aborted cloned porcine fetuses and placentas

Zhang

Wang

Han

et al. 2014

J Assist Reprod Genet

View full text Add to dashboard Cite

Purpose To determine the expression patterns of imprinted genes and their methylation status in aborted cloned porcine fetuses and placentas. Methods RNA and DNA were prepared from fetuses and placentas that were produced by SCNT and controls from artificial insemination. The expression of 18 imprinted genes was determined by quantitative real-time PCR (q-PCR).Bisulfite sequencing PCR (BSP) was conducted to determine the methylation status of PRE-1 short interspersed repetitive element (SINE), satellite DNA and H19 differentially methylated region 3 (DMR3). Results The weight, imprinted gene expression and genomewide DNA methylation patterns were compared between the mid-gestation aborted and normal control samples. The results showed hypermethylation of PRE-1 and satellite sequences, the aberrant expression of imprinted genes, and the hypomethylation of H19 DMR3 occurred in mid-gestation aborted fetuses and placentas. Conclusions Cloned pigs generated by somatic cell nuclear transfer (SCNT) showed a greater ratio of early abortion during mid-gestation than did normal controls because of the incomplete epigenetic reprogramming of the donor cells. Altered expression of imprinted genes and the hypermethylation profile of the repetitive regions (PRE-1 and satellite DNA) may be associated with defective development and early abortion of cloned pigs, emphasizing the importance of epigenetics during pregnancy and implications thereof for patient-specific embryonic stem cells for human therapeutic cloning and improvement of human assisted reproduction.

show abstract

Nuclear reprogramming of cloned embryos and its implications for therapeutic cloning

Cited by 534 publications

References 91 publications

Effects of Donor Fibroblast Cell Type and Transferred Cloned Embryo Number on the Efficiency of Pig Cloning

Effects of Donor Fibroblast Cell Type and Transferred Cloned Embryo Number on the Efficiency of Pig Cloning

Darwin 200: Let's make a mammoth

Altered imprinted gene expression and methylation patterns in mid-gestation aborted cloned porcine fetuses and placentas

Contact Info

Product

Resources

About