Typical Demethylation Events in Cloned Pig Embryos

We investigated whether a genomic demethylation process occurs in pig preimplantation embryos produced by either normal fertilization or somatic cell nuclear transfer. The methylation status of the centromeric satellite and the PRE-1 short interspersed element (SINE) sequences was characterized using bisulfite-sequencing technology. Typical demethylation processes were identified in these repetitive sequences of the cloned donor genome during cleavage, the patterns of which were similar to the ones detected in fertilized counterparts. These findings are different from previous observations with cloned bovine embryos where various repeated regions of the donor genome exhibited aberrant methylation patterns. Our results indicate that species-specific differences exist in modifying the epigenetic status of cloned donor genomes.

[1]  J. Park,et al.  Aberrant methylation of donor genome in cloned bovine embryos , 2001, Nature Genetics.

[2]  J. J. Robinson,et al.  Epigenetic change in IGF2R is associated with fetal overgrowth after sheep embryo culture , 2001, Nature Genetics.

[3]  H. Kim,et al.  Developmental potential and transgene expression of porcine nuclear transfer embryos using somatic cells , 2001, Molecular reproduction and development.

[4]  Yong-Mahn Han,et al.  In Vitro Development of Reconstructed Porcine Oocytes after Somatic Cell Nuclear Transfer1 , 2000, Biology of reproduction.

[5]  R. Prather.  Pigs Is Pigs , 2000, Science.

[6]  Yifan Dai,et al.  Cloned pigs produced by nuclear transfer from adult somatic cells , 2000, Nature.

[7]  A Onishi,et al.  Pig cloning by microinjection of fetal fibroblast nuclei. , 2000, Science.

[8]  W. Reik,et al.  Active demethylation of the paternal genome in the mouse zygote , 2000, Current Biology.

[9]  J. Walter,et al.  Embryogenesis: Demethylation of the zygotic paternal genome , 2000, Nature.

[10]  N. Cordonnier,et al.  Lymphoid hypoplasia and somatic cloning , 1999, The Lancet.

[11]  B. N. Day,et al.  Growth retardation of inner cell mass cells in polyspermic porcine embryos produced in vitro. , 1999, Biology of reproduction.

[12]  H. R. Tervit,et al.  Production of cloned calves following nuclear transfer with cultured adult mural granulosa cells. , 1999, Biology of reproduction.

[13]  K. Latham.  Mechanisms and control of embryonic genome activation in mammalian embryos. , 1999, International review of cytology.

[14]  S. Clark,et al.  Bisulfite sequencing in preimplantation embryos: DNA methylation profile of the upstream region of the mouse imprinted H19 gene. , 1998, Genomics.

[15]  B. N. Day,et al.  Practical considerations for the in vitro production of pig embryos. , 1998, Theriogenology.

[16]  I Wilmut,et al.  Human factor IX transgenic sheep produced by transfer of nuclei from transfected fetal fibroblasts. , 1997, Science.

[17]  I. Wilmut,et al.  "Viable Offspring Derived from Fetal and Adult Mammalian Cells" (1997), by Ian Wilmut et al. , 2014 .

[18]  I. Wilmut,et al.  Sheep cloned by nuclear transfer from a cultured cell line , 1996, Nature.

[19]  W. Reik,et al.  Methylation levels of maternal and paternal genomes during preimplantation development. , 1991, Development.

[20]  M. Monk,et al.  Decrease in DNA methylase activity during preimplantation development in the mouse. , 1991, Development.

[21]  D. Singer,et al.  Identification and DNA sequence of an interspersed repetitive DNA element in the genome of the miniature swine. , 1987, Nucleic acids research.

[22]  V. Chapman,et al.  Methylation patterns of repetitive DNA sequences in germ cells of Mus musculus. , 1984, Nucleic acids research.