Naïve-like conversion enhances the difference in innate in vitro differentiation capacity between rabbit ES cells and iPS cells.

Quality evaluation of pluripotent stem cells using appropriate animal models needs to be improved for human regenerative medicine. Previously, we demonstrated that although the in vitro neural differentiating capacity of rabbit induced pluripotent stem cells (iPSCs) can be mitigated by improving their baseline level of pluripotency, i.e.

Role of retinoic acid and fibroblast growth factor 2 in neural differentiation from cynomolgus monkey (Macaca fascicularis) embryonic stem cells.

Retinoic acid is a widely used factor in both mouse and human embryonic stem cells. It suppresses differentiation to mesoderm and enhances differentiation to ectoderm. Fibroblast growth factor 2 (FGF2) is widely used to induce differentiation to neurons in mice, yet in primates, including humans, it maintains embryonic stem cells in the undifferentiated state.

Naive-like conversion overcomes the limited differentiation capacity of induced pluripotent stem cells.

Although induced pluripotent stem (iPS) cells are indistinguishable from ES cells in their expression of pluripotent markers, their differentiation into targeted cells is often limited. Here, we examined whether the limited capacity of iPS cells to differentiate into neural lineage cells could be mitigated by improving their base-line level of pluripotency, i.e.

Generation of induced pluripotent stem cells in rabbits: potential experimental models for human regenerative medicine.

Human induced pluripotent stem (iPS) cells have the potential to establish a new field of promising regenerative medicine. Therefore, the safety and the efficiency of iPS-derived cells must be tested rigorously using appropriate animal models before human trials can commence. Here, we report the establishment of rabbit iPS cells as the first human-type iPS cells generated from a small laboratory animal species.

Characterization of a novel embryonic stem cell line from an ICSI-derived blastocyst in the African green monkey.

Several cell types from the African green monkey (Cercopithecus aethiops), such as red blood cells, primary culture cells from kidney, and the Vero cell line, are valuable sources for biomedical research and testing. Embryonic stem (ES) cells that are established from blastocysts have pluripotency to differentiate into these and other types of cells. We examined an in vitro culture system of zygotes produced by ICSI in African green monkeys and attempted to establish ES cells.

Continuous observation of rabbit preimplantation embryos in vitro by using a culture device connected to a microscope.

We developed a compact culture device that maintains developing embryos in vitro under constant temperature and CO(2) concentration. Using this device, we cultured rabbit embryos from the pronuclear stage to the hatched blastocyst stage and recorded their development digitally for 7 d. Recorded images were converted to a movie, and the developmental movement of individual embryos was analyzed.

Stable embryonic stem cell lines in rabbits: potential small animal models for human research.

Although embryonic stem (ES) cell lines derived from mice and primates are used extensively, the development of such lines from other mammals is extremely difficult because of their rapid decline in proliferation potential and pluripotency after several passages. This study describes the establishment of rabbit ES cell lines with indefinite proliferation potential. It was found that the feeder cell density determines the fate of rabbit ES cells, and that maximum proliferation potential was obtained when they were cultured on a feeder cell density of one-sixth of the density at confluency.

Collection and culture of primordial germ cells from cynomolgus monkeys ().

To clarify the location of primordial germ cells (PGC) in an embryo of target-age and to examine the culture environment of the PCG. The days of ovulation and fertilization were estimated by measuring the serum concentration of estrogen. Pregnancy was confirmed by measurement of the serum concentration of the beta subunit of macaque chorionic gonadotropin and by ultrasonography.

Differential development of rabbit embryos following microinsemination with sperm and spermatids.

Microinsemination is the technique of delivering male germ cells directly into oocytes. The efficiency of fertilization after microinsemination and subsequent embryo development may vary with the animal species and male germ cells used. The present study was undertaken to observe the in vitro and in vivo developmental ability of rabbit embryos following microinsemination with male germ cells at different stages.