Biomaterial Database

Nuclear reprogramming of cloned embryos produced in vitro. 2003

Y M Han, and Y K Kang, and D B Koo, and K K Lee

Laboratory of Development and Differentiation, Korea Research Institute of Bioscience and Biotechnology, PO Box 115, Yusong, Daejeon 305-600, South Korea. ymhan@kribb.re.kr

Despite the fact that cloned animals derived from somatic cells have been successfully generated in a variety of mammalian species, there are still many unsolved problems with current cloning technology. Somatic cell nuclear transfer has shown several developmental aberrancies, including a high rate of abortion during early gestation and increased perinatal death. One cause of these developmental failures of cloned embryos may reside in the epigenetic reprogramming of somatic donor genome. In mammals, DNA methylation is an essential process in the regulation of transcription during embryonic development and is generally associated with gene silencing. A genome-wide demethylation may be a prerequisite for the formation of pluripotent stem cells that are important for later development. We analyzed methylation patterns in cloned bovine embryos to monitor the epigenetic reprogramming process of donor genomic DNA. Aberrant methylation profiles of cloned bovine embryos were observed in various genomic regions, except in single-copy gene sequences. The overall genomic methylation status of cloned embryos was quite different from that of normal embryos produced in vitro or in vivo. These results suggest that the developmental failures of cloned embryos may be due to incomplete epigenetic reprogramming of donor genomic DNA. We expect that advances in understanding the molecular events for reprogramming of donor genome will contribute to clarify the developmental defects of cloned embryos.

UI	MeSH Term	Description	Entries
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D002467	Cell Nucleus	Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)	Cell Nuclei,Nuclei, Cell,Nucleus, Cell
D005314	Embryonic and Fetal Development	Morphological and physiological development of EMBRYOS or FETUSES.	Embryo and Fetal Development,Prenatal Programming,Programming, Prenatal
D005818	Genetic Engineering	Directed modification of the gene complement of a living organism by such techniques as altering the DNA, substituting genetic material by means of a virus, transplanting whole nuclei, transplanting cell hybrids, etc.	Genetic Intervention,Engineering, Genetic,Intervention, Genetic,Genetic Interventions,Interventions, Genetic
D000013	Congenital Abnormalities	Malformations of organs or body parts during development in utero.	Birth Defects,Congenital Defects,Deformities,Fetal Anomalies,Fetal Malformations,Abnormalities, Congenital,Defects, Congenital,Abnormality, Congenital,Anomaly, Fetal,Birth Defect,Congenital Abnormality,Congenital Defect,Defect, Birth,Defect, Congenital,Deformity,Fetal Anomaly,Fetal Malformation,Malformation, Fetal
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013552	Swine	Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).	Phacochoerus,Pigs,Suidae,Warthogs,Wart Hogs,Hog, Wart,Hogs, Wart,Wart Hog
D053652	Nuclear Transfer Techniques	Methods of implanting a CELL NUCLEUS from a donor cell into an enucleated acceptor cell.	Nuclear Transplantation,Somatic Cell Nuclear Transfer Technique,Nuclear Transfer Technique,Transplantation, Nuclear
D018507	Gene Expression Regulation, Developmental	Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action during the developmental stages of an organism.	Developmental Gene Expression Regulation,Embryologic Gene Expression Regulation,Gene Expression Regulation, Embryologic,Regulation of Gene Expression, Developmental,Regulation of Gene Expression, Embryologic,Regulation, Gene Expression, Developmental,Regulation, Gene Expression, Embryologic
D019175	DNA Methylation	Addition of methyl groups to DNA. DNA methyltransferases (DNA methylases) perform this reaction using S-ADENOSYLMETHIONINE as the methyl group donor.	DNA Methylations,Methylation, DNA,Methylations, DNA