Genetic Tagging During Human Mesoderm Differentiation Reveals Tripotent Lateral Plate Mesodermal Progenitors

Area of Science:

• Developmental biology
• Stem cell research
• Genomics

Background:

• Clonal studies are vital for understanding stem and progenitor cell potential.
• The clonal origins of germ layer lineages during early embryogenesis remain poorly understood.
• Previous research primarily focused on self-renewing stem cell clones.

Purpose of the Study:

• To investigate the ontogeny of hematopoietic, endothelial, and mesenchymal lineages from human embryonic mesoderm.
• To analyze progenitor clones with limited self-renewal capabilities.
• To understand the clonal origins of early embryogenesis lineages.

Main Methods:

• Utilized lentiviral tagging and vector integration site analysis (VISA).
• Employed high-throughput sequencing for comprehensive analysis.
• Focused on progenitor clones with minimal clonal duplication.

Main Results:

• Identified the critical influence of sampling on interpreting lentiviral tag sharing in complex populations.
• Developed a quantitative framework to estimate undersampling.
• Revealed tripotent mesodermal progenitors originating from pluripotent stem cells.
• Demonstrated subsequent bifurcation into bipotent endothelial/hematopoietic or endothelial/mesenchymal progenitors.

Conclusions:

• Tripotent mesodermal progenitors are key to early human development.
• Understanding progenitor behavior is crucial for interpreting lineage potential.
• This research provides insights into the early differentiation pathways of mesodermal cells.