The introduction of nuclear transfer (NT) and other technologies that involve embryo reconstruction require us to reinvestigate patterns of mitochondrial DNA (mtDNA) transmission, transcription and replication. MtDNA is a 16.6 kb genome located within each mitochondrion. The number of mitochondria and mtDNA copies per organelle is specific to each cell type. MtDNA is normally transmitted throug...

Recent advances in nuclear transfer technology for derivation of patient-specific stem cells have opened up new avenues of therapy for various human diseases. However, a major bottleneck is the severe shortage of human donor oocytes. Egg-sharing in return for subsidized fertility treatment has been suggested as an ethically justifiable and practical solution to ease the shortage of donor oocyte...

During the past thirty years, basic and experimental studies on classical (superovulation; non-surgical recovery and transfer of cattle embryos) and advanced embryo technologies (in vitro embryo production; cloning by somatic cell nuclear transfer) have generated structural and functional information on oocyte development and quality, fertilisation and conceptus development. This information ha...

Somatic cell nuclear transfer (SCNT) cloning is the sole reproductive engineering technology that endows the somatic cell genome with totipotency. Since the first report on the birth of a cloned sheep from adult somatic cells in 1997, many technical improvements in SCNT have been made by using different epigenetic approaches, including enhancement of the levels of histone acetylation in the chr...

IFFERENTIATION has long been conceived of as a series of binary decisions. Wsddington's epigenetic landscape (1940) provides a particularly vivid visual image of this concept: differentiation is likened to the path taken by a ball as it rolls down a sloped surface grooved by valleys. Similarly, according to Stuart Kauffman's binary model (1973), early choices limit later probabilities for chang...

Low development of somatic cell nuclear transfer embryos could be due to the incomplete DNA methylation reprogramming, and Dnmt1s existing in donor cells may be one cause of this disrupted DNA methylation reprogramming. However, the reprogramming pattern of Dnmt1s and its effect on DNA methylation reprogramming in cloned embryos remain poorly understood. Here, we displayed that along with the s...

background: plants are among promising and suitable platform systems for production of recombinant biopharmaceutical proteins due to several features such as safety, no need for fermentation, inexpensive investment, and fast and easy scale-up. human insulin is one of the most widely used medicines in the world. up to now different expression systems including escherichia coli, yeast and cho hav...

clinical application of embryonic stem (es) cells faces difficulties regarding tissue rejection as well as ethical limitations. one solution for these issues is to reprogram somatic cells by the injection of their nucleus into an enucleated oocyte or zygote. however, technical complications and ethical considerations have impeded the therapeutic implications of this technology. an approach whic...

agrobacterium tumefaciens is capable of gene transfer to both plant and non-plant organisms. indeed, upon infection of eukaryotic cells, agrobacterium tumefaciens transfers a piece of its tumor inducing (ti)-plasmid, called t-dna, to the host cell nucleus, which subsequently integrates into the host genome. the vird2 virulence protein which has relaxase endonuclease activities covalently binds ...