Biomaterial Database

Nuclear transfer in mammals: recent developments and future perspectives. 1998

E Wolf, and V Zakhartchenko, and G Brem

Lehrstuhl für Molekulare Tierzucht und Haustiergenetik/Genzentrum, Ludwig-Maximilians-Universität, München, Germany.

A clone can be defined as a set of genetically identical animals. Small clones of two or occasionally up to four identical animals can be obtained by embryo splitting or blastomere separation. Embryo cloning by nuclear transfer involves the transfer of genetic material from a donor cell (karyoplast) to the cytoplasm of an oocyte or zygote from which the genetic material has been removed (cytoplast). In farm animals, metaphase II oocytes are most widely used as cytoplasts. There are now many factors known to influence the efficiency of embryo cloning by nuclear transfer. These include stage of development and cell cycle of donor cells, the choice of the recipient cell, the methods for activation of oocytes, the cell cycle coordination between donor cell and recipient cytoplast, and the method for fusion between nuclear donor and recipient cytoplast. Recent progress in cloning embryos and animals from cultured cells of embryonic, fetal, or adult origin offers a wide spectrum of potential applications of nuclear transfer, such as the unlimited multiplication of elite embryos or animals from selected matings and the potential for precise genetic modification of farm animals for gene farming or xenotransplantation.

UI	MeSH Term	Description	Entries
D008322	Mammals	Warm-blooded vertebrate animals belonging to the class Mammalia, including all that possess hair and suckle their young.	Mammalia,Mammal
D009865	Oocytes	Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM).	Ovocytes,Oocyte,Ovocyte
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D004624	Embryo Transfer	The transfer of mammalian embryos from an in vivo or in vitro environment to a suitable host to improve pregnancy or gestational outcome in human or animal. In human fertility treatment programs, preimplantation embryos ranging from the 4-cell stage to the blastocyst stage are transferred to the uterine cavity between 3-5 days after FERTILIZATION IN VITRO.	Blastocyst Transfer,Tubal Embryo Transfer,Tubal Embryo Stage Transfer,Embryo Transfers,Transfer, Embryo,Transfers, Embryo
D005260	Female		Females
D005544	Forecasting	The prediction or projection of the nature of future problems or existing conditions based upon the extrapolation or interpretation of existing scientific data or by the application of scientific methodology.	Futurology,Projections and Predictions,Future,Predictions and Projections
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
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
D019976	Cloning, Organism	The formation of one or more genetically identical organisms derived by vegetative reproduction from a single cell. The source nuclear material can be embryo-derived, fetus-derived, or taken from an adult somatic cell.	Cloning, Embryo,Cloning, Human,Embryo Cloning,Human Cloning,Cloning,Clonings, Embryo,Clonings, Human,Clonings, Organism,Embryo Clonings,Human Clonings,Organism Cloning,Organism Clonings