Mouse SCNT ESCs have lower somatic mutation load than syngeneic iPSCs

Area of Science:

• Stem Cell Biology
• Genetics
• Reproductive Biology

Background:

• Induced pluripotent stem cells (iPSCs) are generated by reprogramming somatic cells using ectopic factors.
• Concerns exist regarding genetic aberrations, such as somatic mutations, in iPSCs, potentially limiting their clinical applications.

Purpose of the Study:

• To investigate whether increased somatic mutations in iPSCs are a byproduct of current reprogramming techniques.
• To compare the mutation profiles of iPSCs and embryonic stem cells (ESCs) derived via somatic cell nuclear transfer (SCNT).

Main Methods:

• Reprogramming of mouse embryonic fibroblasts into iPSCs.
• Generation of ESCs using somatic cell nuclear transfer (SCNT ESCs).
• Exome sequencing of both iPSC and SCNT ESC lines.

Main Results:

• SCNT ESCs exhibited a significantly lower mutation load compared to iPSCs from a syngeneic background.
• One SCNT-ESC line showed no detectable exome mutations.
• Unique mutations were identified in every iPSC line, whereas SCNT-ESC lines had either no mutations or shared pre-existing mutations.

Conclusions:

• Somatic cell nuclear transfer ESCs present a lower mutation burden than iPSCs.
• Current iPSC reprogramming methods may introduce unique somatic mutations.
• Improvements in iPSC generation methods are needed for more physiologically relevant and clinically applicable cell lines.