Limited demethylation leaves mosaic-type methylation states in cloned bovine pre-implantation embryos

Cited 186 time in scopus
Metadata Downloads
Title
Limited demethylation leaves mosaic-type methylation states in cloned bovine pre-implantation embryos
Author(s)
Yong Kook KangJung Sun Park; Deog Bon Koo; Young Hee Choi; Sun-Uk Kim; Kyung Kwang Lee; Yong Mahn Han
Bibliographic Citation
EMBO Journal, vol. 21, no. 5, pp. 1092-1100
Publication Year
2002
Abstract
Cloning by nuclear transfer (NT) has been riddled with difficulties: most clones die before birth and survivors frequently display growth abnormalities. The cross-species similarity in abnormalities observed in cloned fetuses/animals leads us to suspect the fidelity of epigenetic reprogramming of the donor genome. Here, we found that single-copy sequences, unlike satellite sequences, are demethylated in pre-implantation NT embryos. The differential demethylation pattern between genomic sequences was confirmed by analyzing single blastocysts. It suggests selective demethylation of other developmentally important genes in NT embryos. We also observed a reverse relationship between methylation levels and inner cell mass versus trophectoderm (ICM/TE) ratios, which was found to be a result of another type of differential demethylation occurring in NT blastocysts where unequal methylation was maintained between ICM and TE regions. TE-localized methylation aberrancy suggests a widespread gene dysregulation in an extra-embryonic region, thereby resulting in placental dysfunction familiar to cloned fetuses/animals. These differential demethylations among genomic sequences and between differently allocated cells produce varied overall, but specified, methylation patterns, demonstrating that epigenetic reprogramming occurs in a limited fashion in NT embryos.
Keyword
Pre-implantation embryosBovineCloningDemethylationEpigenetic reprogramming
ISSN
0261-4189
Publisher
Wiley
DOI
http://dx.doi.org/10.1093/emboj/21.5.1092
Type
Article
Appears in Collections:
Aging Convergence Research Center > 1. Journal Articles
Ochang Branch Institute > Division of National Bio-Infrastructure > Futuristic Animal Resource & Research Center > 1. Journal Articles
Files in This Item:
  • There are no files associated with this item.


Items in OpenAccess@KRIBB are protected by copyright, with all rights reserved, unless otherwise indicated.