Generation of Cynomolgus Monkey Chimeric Fetuses using Embryonic Stem Cells

Abstract

Because of their similarity to humans, non-human primates are important models for studying human disease and developing therapeutic strategies. Establishment of chimeric animals using embryonic stem cells (ESCs) could help with these investigations, but has not so far been achieved. Here, we show that cynomolgus monkey ESCs (cESCs) grown in adjusted culture conditions are able to incorporate into host embryos and develop into chimeras with contribution in all three germ layers and in germ cell progenitors. Under the optimized culture conditions, which are based on an approach developed previously for naive human ESCs, the cESCs displayed altered growth properties, gene expression profiles, and self-renewal signaling pathways, suggestive of an altered naive-like cell state. Thus our findings show that it is feasible to generate chimeric monkeys using ESCs and open up new avenues for the use of non-human primate models to study both pluripotency and human disease.

The pluripotent state in mouse and human

“…By contrast, using a modification of the naïve culture system of Gafni et al (2013) to convert cynomolgus monkey primed ESCs to a naïve state, Chen et al (2015) were able to demonstrate contributions of the resulting naïve cells to multiple tissues representative of all three embryonic germ layers, including germline progenitors, in two foetuses following injection of the stem cells into host morulae and transfer back to a foster mother. Levels of chimerism were once again low, however, and the experiment, which required use of specific combinations of culture media to ensure stem cell survival during embryo culture, was not attempted with primed cells.…”

Monkey kingdom

“…And last year, Ji made the world's first chimeric monkeys using embryonic stem cells 4 , an advance that could make the production of genetically modified animals even easier. The question now is whether these genetically modified monkeys will propel understanding of human brain function and dysfunction to a higher level.…”

A fully defined static suspension culture system for large-scale human embryonic stem cell production

“…We compared the cell proliferation of hESC spheres suspended in different medium types, including conditioned medium (CM) 25,26 , a suspension culture medium for monkey embryonic stem cells (3:1) 27 , conventional culture medium without bFGF (EB), and Essential 8 TM (E8) medium 28 (Fig. 1a).…”