Differential Developmental Ability of Embryos Cloned from Tissue-Specific Stem Cells

Abstract

Although cloning animals by somatic cell nuclear transfer is generally inefficient, the use of certain nuclear donor cell types may significantly improve or deteriorate outcomes. We evaluated whether two multipotent stem cell lines produced in vitro-neural stem cells (NSCs) and mesenchymal stem cells (MSCs)-could serve as nuclear donors for nuclear transfer cloning. Most (76%) NSCderived embryos survived the two-cell-to-four-cell transition, the stage when the major zygotic gene activation occurs. Consistent with this observation, the expression patterns of zygotically active genes were better in NSCderived embryos than in fibroblast clone embryos, which arrested at the two-cell stage more frequently. Embryo transfer experiments demonstrated that at least some of these NSC embryos had the ability to develop to term fetuses (1.6%, 3/189). In contrast, embryos reconstructed using MSCs showed a low rate of in vitro development and never underwent implantation in vivo. Chromosomal analysis of the donor MSCs revealed very frequent aneuploidy, which probably impaired the potential for development of their derived clones. This is the first demonstration that tissue-specific multipotent stem cells produced in vitro can serve as donors of nuclei for cloning mice; however, these cells may be prone to chromosomal aberrations, leading to high embryonic death rates. We found previously that hematopoietic stem cells (HSCs) are very inefficient donor cells because of their failure to activate the genes essential for embryonic development. Taken together, our data led us to conclude that tissuespecific stem cells in mice, namely NSCs, MSCs, and HSCs, exhibited marked variations in the ability to produce cloned offspring and that this ability varies according to both the epigenetic and genetic status of the original genomes.

Recent advancements in cloning by somatic cell nuclear transfer

“…Neural stem cells derived from foetal or neonatal brains could be cloned to produce normal offspring by SCNT [31,44]. These results suggest that neural lineage cells lose their reprogrammability as they differentiate.…”

“…All experiments were undertaken using male donor cells with a (B6Â129) F 1 genetic background, except for female primordial germ cells (PGCs). This is based on data both published [30,44,45,47,56] and unpublished (A. Ogura, K. Inoue, unpublished data). The birth rates were calculated, including placenta-only conceptuses.…”

“…The birth rates were calculated, including placenta-only conceptuses. Results using donor cells with incomplete genomic imprinting such as early PGCs [57] or with abnormal chromosomal constitutions such as long-cultured mesenchymal stem cells [44] or cancer cells [58] have been omitted here. TSA, trichostatin A.…”

Production Efficiency and Telomere Length of the Cloned Pigs Following Serial Somatic Cell Nuclear Transfer

“…As reported by Matsumoto et al [25,26], pSGPs are pluripotent endodermal tissue progenitor cells that produce albumin and insulin after differentiation into hepatic and pancreatic lineages. At this point in time, the advantages of using pluripotent tissue progenitor cells as donor cells in SCNT have not been fully clarified [27,[37][38][39][40][41][42], but pSGPs are considered promising donor cells for efficient production of cloned pigs.A microsatellite analysis was conducted by sending samples obtained from the cloned pigs, donor cells and recipients to a company that specializes in porcine parentage verification (Prescribe …”

Nuclear reprogramming: what has been done and potential avenues for improvements

“…Studies from independent groups comparing the efficiency of nuclear reprogramming of NT embryos reconstructed with stem cells isolated from adult tissue or with differentiated cells resulted in comparable outcomes [95][96][97]. However, it is likely that there are differences between the sources of adult stem cells.…”