Asymmetric division of a mother stem cell gives rise to one, analogous to the mother, daughter cell, and to a second daughter cell that takes the path of further differentiation. Stem cells are progenitor cells of the substituting young cells. The sooner the organism destroys the cells that emerged a certain time ago and replaces them with the new (i.e., the higher is the regeneration tempo), the younger the organism is. The replacement of cells happens even if the cells are in perfect condition. In the organisms of most multicellular animals and humans, the regeneration process always takes place: destruction of old cells and their replacement with the new. These results suggest that somatic cell cloning methods could be used to restore endangered, or even extinct, species and populations.Īll molecules, structures, cells in organisms are subjected to destruction during the process of vital activities. The gaur nuclei were shown to direct normal fetal development, with differentiation into complex tissue and organs, even though the mitochondrial DNA (mtDNA) within all the tissue types evaluated was derived exclusively from the recipient bovine oocytes. Microsatellite marker and cytogenetic analyses confirmed that the nuclear genome of the cloned animals was gaurus in origin. Three of the fetuses were electively removed at days 46 to 54 of gestation, and two continued gestation longer than 180 (ongoing) and 200 days, respectively. Twelve percent of the reconstructed oocytes developed to the blastocyst stage, and 18% of these embryos developed to the fetal stage when transferred to surrogate mothers. Somatic cells from a gaur bull (Bos gaurus), a large wild ox on the verge of extinction, (Species Survival Plan < 100 animals) were electrofused with enucleated oocytes from domestic cows. Here we show that interspecies nuclear transfer can be used to clone an endangered species with normal karyotypic and phenotypic development through implantation and the late stages of fetal growth. Despite increasing interest in using cloning to rescue endangered species, successful interspecies nuclear transfer has not been previously described, and only a few reports of in vitro embryo formation exist. Approximately 100 species become extinct a day.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |