Genetic Engineering of Human Embryonic Stem Cells for Precise Cell Fate Tracing during Human Lineage Development

This study introduces methods for creating lineage-tracing systems in human embryonic stem cells (hESCs). These systems allow scientists to track the development of specific cell types and their progeny. The researchers found that the AAVS1 locus is a good place to insert the tracing system. They also discovered that the Cre-LoxP and Flp-FRT systems, which are used for gene recombination, are very sensitive in human cells, potentially leading to inaccurate tracing. To improve accuracy, the team modified the LoxP recombination site and used tamoxifen-controllable systems. These improvements allowed them to trace human PAX6+ neuroectoderm cells and map their development into neural lineages, both in lab cultures and in animal models.

• 1
  The AAVS1 locus in human cells is suitable for integrating conditional reporters for reliable transgene expression during lineage tracing.
• 2
  The Cre-LoxP and Flp-FRT systems are highly sensitive in human cells, potentially leading to inaccurate lineage labeling due to minimal recombinase expression.
• 3
  Modifying the LoxP recombination site and using tamoxifen-controllable CreERT2-LoxP and FlpERT2-FRT systems can improve the accuracy and temporal control of lineage tracing in human cells.