Mouse cloning and somatic cell reprogramming using electrofused blastomeres

Abstract

Mouse cloning from fertilized eggs can assist development of approaches for the production of "genetically tailored" human embryonic stem (ES) cell lines that are not constrained by the limitations of oocyte availability. However, to date only zygotes have been successfully used as recipients of nuclei from terminally differentiated somatic cell donors leading to ES cell lines. In fertility clinics, embryos of advanced embryonic stages are usually stored for future use, but their ability to support the derivation of ES cell lines via somatic nuclear transfer has not yet been proved. Here, we report that two-cell stage electrofused mouse embryos, arrested in mitosis, can support developmental reprogramming of nuclei from donor cells ranging from blastomeres to somatic cells. Live, full-term cloned pups from embryonic donors, as well as pluripotent ES cell lines from embryonic or somatic donors, were successfully generated from these reconstructed embryos. Advanced stage pre-implantation embryos were unable to develop normally to term after electrofusion and transfer of a somatic cell nucleus, indicating that discarded pre-implantation human embryos could be an important resource for research that minimizes the ethical concerns for human therapeutic cloning. Our approach provides an attractive and practical alternative to therapeutic cloning using donated oocytes for the generation of patient-specific human ES cell lines.

Genome-Wide Association Study of Piglet Uniformity and Farrowing Interval

“…Furthermore, fetal lipid deposition is mainly increased in the gestational period (Haggarty, 2002 ). During the course of reproduction, pre-implantation stages are important for reproductive and stem cell biology (Riaz et al, 2011 ). The UBTFL1 gene, also known as Hmgpi , is a preimplantation-specific gene and is involved in early development and implantation.…”

Cycling through developmental decisions: how cell cycle dynamics control pluripotency, differentiation and reprogramming

“…For example, mouse zygotes and electro-fused blastomeres arrested in mitosis can acquire a reprogramming capacity in SCNT (Egli et al, 2007;Riaz et al, 2011). However, a recent study has shown that even the cytoplasm of interphase twocell mouse embryos can reprogram somatic cells in SCNT, if the donor nucleus and recipient cytoplasm are synchronized (Kang et al, 2014).…”

Nuclear reprogramming by interphase cytoplasm of two-cell mouse embryos

“…However, these poorly defined maternal factors presumably decline sharply after fertilization since cytoplasm of pronuclear stage zygotes is reportedly inactive 4 , 5 . Recent evidence suggests that zygotic cytoplasm, if maintained at metaphase (M-phase) can also support derivation of embryonic stem cells (ESCs) following SCNT 6 - 8 , albeit at low efficiency. This led to the conclusion that critical oocyte reprogramming factors present in M-phase but not in interphase cytoplasm are “trapped” inside the nucleus during interphase and effectively removed during enucleation 9 .…”