Generation of mouse-human chimeric embryos

Area of Science:

• Developmental Biology
• Stem Cell Biology
• Chimerism

Background:

• Human pluripotent stem cells (hPSCs) are crucial for regenerative medicine.
• Generating mouse-human chimeric embryos allows for in vivo study of human cell development.
• Converting primed hPSCs to a naive state is essential for efficient chimerism.

Purpose of the Study:

• To establish a protocol for converting primed hPSCs to naive hPSCs.
• To generate mouse-human chimeric embryos using these converted naive hPSCs.
• To evaluate the potential of this protocol for studying hPSC development and generating human tissues in vivo.

Main Methods:

• Primed hPSCs treated with a mammalian target of rapamycin inhibitor (Torin1).
• Cells cultured in 2iLI medium on mouse embryonic fibroblasts to establish naive hPSCs.
• Naive hPSCs injected into mouse blastocysts to create chimeric embryos.
• Human cell contribution quantified using next-generation sequencing of 18S ribosomal DNA amplicons.

Main Results:

• Successful conversion of primed hPSCs to naive hPSCs with mouse embryonic stem cell morphology.
• Generation of E17.5 mouse embryos containing 0.1-4.0% human cells.
• Demonstrated suitability of the protocol for studying hPSC development in a mammalian environment.

Conclusions:

• A robust protocol for generating naive hPSCs from primed cells is described.
• This method enables the creation of mouse-human chimeric embryos with significant human cell contribution.
• The protocol holds promise for advancing research in human cell development, tissue engineering, and organ generation in animals.